/* GStreamer * * Copyright (C) 2001-2002 Ronald Bultje * 2006 Edgard Lima * 2009 Texas Instruments, Inc - http://www.ti.com/ * * gstv4l2bufferpool.c V4L2 buffer pool class * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, * Boston, MA 02110-1301, USA. */ #ifdef HAVE_CONFIG_H # include #endif #ifndef _GNU_SOURCE # define _GNU_SOURCE /* O_CLOEXEC */ #endif #include #include #include #include #include "gst/video/video.h" #include "gst/video/gstvideometa.h" #include "gst/video/gstvideopool.h" #include "gst/allocators/gstdmabuf.h" #include #include "gstv4l2object.h" #include #include GST_DEBUG_CATEGORY_STATIC (v4l2bufferpool_debug); GST_DEBUG_CATEGORY_STATIC (CAT_PERFORMANCE); #define GST_CAT_DEFAULT v4l2bufferpool_debug #define GST_V4L2_IMPORT_QUARK gst_v4l2_buffer_pool_import_quark () /* * GstV4l2BufferPool: */ #define gst_v4l2_buffer_pool_parent_class parent_class G_DEFINE_TYPE (GstV4l2BufferPool, gst_v4l2_buffer_pool, GST_TYPE_BUFFER_POOL); enum _GstV4l2BufferPoolAcquireFlags { GST_V4L2_BUFFER_POOL_ACQUIRE_FLAG_RESURRECT = GST_BUFFER_POOL_ACQUIRE_FLAG_LAST, GST_V4L2_BUFFER_POOL_ACQUIRE_FLAG_LAST }; /* Buffer state flags */ enum _GstV4l2BufferState { /* Buffer is free (either on the GstBufferPool free queue, or no GstBuffer has * been allocated yet) */ BUFFER_STATE_FREE = 0, /* Buffer had outstanding external users */ BUFFER_STATE_OUTSTANDING = 1, /* Buffer is on one of the kernel queues */ BUFFER_STATE_QUEUED = 2, }; static void gst_v4l2_buffer_pool_complete_release_buffer (GstBufferPool * bpool, GstBuffer * buffer, gboolean queued); static gboolean gst_v4l2_is_buffer_valid (GstBuffer * buffer, GstV4l2MemoryGroup ** out_group, gboolean check_writable) { GstMemory *mem = gst_buffer_peek_memory (buffer, 0); gboolean valid = FALSE; if (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY)) goto done; if (gst_is_dmabuf_memory (mem)) mem = gst_mini_object_get_qdata (GST_MINI_OBJECT (mem), GST_V4L2_MEMORY_QUARK); if (mem && gst_is_v4l2_memory (mem)) { GstV4l2Memory *vmem = (GstV4l2Memory *) mem; GstV4l2MemoryGroup *group = vmem->group; gint i; if (group->n_mem != gst_buffer_n_memory (buffer)) goto done; for (i = 0; i < group->n_mem; i++) { if (group->mem[i] != gst_buffer_peek_memory (buffer, i)) goto done; if (check_writable && !gst_memory_is_writable (group->mem[i])) goto done; } valid = TRUE; if (out_group) *out_group = group; } done: return valid; } static void gst_v4l2_buffer_pool_resize_buffer (GstBufferPool * bpool, GstBuffer * buffer) { GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool); GstV4l2MemoryGroup *group; if (gst_v4l2_is_buffer_valid (buffer, &group, TRUE)) { gst_v4l2_allocator_reset_group (pool->vallocator, group); } else { GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY); } } static GstFlowReturn gst_v4l2_buffer_pool_copy_buffer (GstV4l2BufferPool * pool, GstBuffer * dest, GstBuffer * src) { const GstVideoFormatInfo *finfo = pool->caps_info.finfo; GST_LOG_OBJECT (pool, "copying buffer"); if (finfo && (finfo->format != GST_VIDEO_FORMAT_UNKNOWN && finfo->format != GST_VIDEO_FORMAT_ENCODED)) { GstVideoFrame src_frame, dest_frame; GST_DEBUG_OBJECT (pool, "copy video frame"); /* we have raw video, use videoframe copy to get strides right */ if (!gst_video_frame_map (&src_frame, &pool->caps_info, src, GST_MAP_READ)) goto invalid_buffer; if (!gst_video_frame_map (&dest_frame, &pool->caps_info, dest, GST_MAP_WRITE)) { gst_video_frame_unmap (&src_frame); goto invalid_buffer; } gst_video_frame_copy (&dest_frame, &src_frame); gst_video_frame_unmap (&src_frame); gst_video_frame_unmap (&dest_frame); } else { GstMapInfo map; gsize filled_size; GST_DEBUG_OBJECT (pool, "copy raw bytes"); if (!gst_buffer_map (src, &map, GST_MAP_READ)) goto invalid_buffer; filled_size = gst_buffer_fill (dest, 0, map.data, gst_buffer_get_size (src)); gst_buffer_unmap (src, &map); gst_buffer_resize (dest, 0, filled_size); } gst_buffer_copy_into (dest, src, GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS, 0, -1); GST_CAT_LOG_OBJECT (CAT_PERFORMANCE, pool, "slow copy into buffer %p", dest); return GST_FLOW_OK; invalid_buffer: { GST_ERROR_OBJECT (pool, "could not map buffer"); return GST_FLOW_ERROR; } } struct UserPtrData { GstBuffer *buffer; gboolean is_frame; GstVideoFrame frame; GstMapInfo map; }; static GQuark gst_v4l2_buffer_pool_import_quark (void) { static GQuark quark = 0; if (quark == 0) quark = g_quark_from_string ("GstV4l2BufferPoolUsePtrData"); return quark; } static void _unmap_userptr_frame (struct UserPtrData *data) { if (data->is_frame) gst_video_frame_unmap (&data->frame); else gst_buffer_unmap (data->buffer, &data->map); if (data->buffer) gst_buffer_unref (data->buffer); g_free (data); } static GstFlowReturn gst_v4l2_buffer_pool_import_userptr (GstV4l2BufferPool * pool, GstBuffer * dest, GstBuffer * src) { GstFlowReturn ret = GST_FLOW_OK; GstV4l2MemoryGroup *group = NULL; GstMapFlags flags; const GstVideoFormatInfo *finfo = pool->caps_info.finfo; struct UserPtrData *data = NULL; GST_LOG_OBJECT (pool, "importing userptr"); /* get the group */ if (!gst_v4l2_is_buffer_valid (dest, &group, TRUE)) goto not_our_buffer; if (V4L2_TYPE_IS_OUTPUT (pool->obj->type)) flags = GST_MAP_READ; else flags = GST_MAP_WRITE; data = g_new0 (struct UserPtrData, 1); if (finfo && (finfo->format != GST_VIDEO_FORMAT_UNKNOWN && finfo->format != GST_VIDEO_FORMAT_ENCODED)) { gsize size[GST_VIDEO_MAX_PLANES] = { 0, }; gint i; data->is_frame = TRUE; if (!gst_video_frame_map (&data->frame, &pool->caps_info, src, flags)) goto invalid_buffer; for (i = 0; i < GST_VIDEO_FORMAT_INFO_N_PLANES (finfo); i++) { if (GST_VIDEO_FORMAT_INFO_IS_TILED (finfo)) { gint tinfo = GST_VIDEO_FRAME_PLANE_STRIDE (&data->frame, i); size[i] = GST_VIDEO_TILE_X_TILES (tinfo) * GST_VIDEO_TILE_Y_TILES (tinfo) * GST_VIDEO_FORMAT_INFO_TILE_SIZE (finfo, i); } else { size[i] = GST_VIDEO_FRAME_PLANE_STRIDE (&data->frame, i) * GST_VIDEO_FRAME_COMP_HEIGHT (&data->frame, i); } } /* In the single planar API, planes must be contiguous in memory and * therefore they must have expected size. ie: no padding. * To check these conditions, we check that plane 'i' start address * + plane 'i' size equals to plane 'i+1' start address */ if (!V4L2_TYPE_IS_MULTIPLANAR (pool->obj->type)) { for (i = 0; i < (GST_VIDEO_FORMAT_INFO_N_PLANES (finfo) - 1); i++) { const struct v4l2_pix_format *pix_fmt = &pool->obj->format.fmt.pix; gpointer tmp; gint estride = gst_video_format_info_extrapolate_stride (finfo, i, pix_fmt->bytesperline); guint eheight = GST_VIDEO_FORMAT_INFO_SCALE_HEIGHT (finfo, i, pix_fmt->height); tmp = ((guint8 *) data->frame.data[i]) + estride * eheight; if (tmp != data->frame.data[i + 1]) goto non_contiguous_mem; } } if (!gst_v4l2_allocator_import_userptr (pool->vallocator, group, data->frame.info.size, finfo->n_planes, data->frame.data, size)) goto import_failed; } else { gpointer ptr[1]; gsize size[1]; data->is_frame = FALSE; if (!gst_buffer_map (src, &data->map, flags)) goto invalid_buffer; ptr[0] = data->map.data; size[0] = data->map.size; if (!gst_v4l2_allocator_import_userptr (pool->vallocator, group, data->map.size, 1, ptr, size)) goto import_failed; } data->buffer = gst_buffer_ref (src); gst_mini_object_set_qdata (GST_MINI_OBJECT (dest), GST_V4L2_IMPORT_QUARK, data, (GDestroyNotify) _unmap_userptr_frame); gst_buffer_copy_into (dest, src, GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS, 0, -1); return ret; not_our_buffer: { GST_ERROR_OBJECT (pool, "destination buffer invalid or not from our pool"); return GST_FLOW_ERROR; } invalid_buffer: { GST_ERROR_OBJECT (pool, "could not map buffer"); g_free (data); return GST_FLOW_ERROR; } non_contiguous_mem: { GST_ERROR_OBJECT (pool, "memory is not contiguous or plane size mismatch"); _unmap_userptr_frame (data); return GST_FLOW_ERROR; } import_failed: { GST_ERROR_OBJECT (pool, "failed to import data"); _unmap_userptr_frame (data); return GST_FLOW_ERROR; } } static GstFlowReturn gst_v4l2_buffer_pool_import_dmabuf (GstV4l2BufferPool * pool, GstBuffer * dest, GstBuffer * src) { GstV4l2MemoryGroup *group = NULL; GstMemory *dma_mem[GST_VIDEO_MAX_PLANES] = { 0 }; guint n_mem = gst_buffer_n_memory (src); gint i; GST_LOG_OBJECT (pool, "importing dmabuf"); if (!gst_v4l2_is_buffer_valid (dest, &group, TRUE)) goto not_our_buffer; if (n_mem > GST_VIDEO_MAX_PLANES) goto too_many_mems; for (i = 0; i < n_mem; i++) dma_mem[i] = gst_buffer_peek_memory (src, i); if (!gst_v4l2_allocator_import_dmabuf (pool->vallocator, group, n_mem, dma_mem)) goto import_failed; gst_mini_object_set_qdata (GST_MINI_OBJECT (dest), GST_V4L2_IMPORT_QUARK, gst_buffer_ref (src), (GDestroyNotify) gst_buffer_unref); gst_buffer_copy_into (dest, src, GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS, 0, -1); return GST_FLOW_OK; not_our_buffer: { GST_ERROR_OBJECT (pool, "destination buffer invalid or not from our pool"); return GST_FLOW_ERROR; } too_many_mems: { GST_ERROR_OBJECT (pool, "could not map buffer"); return GST_FLOW_ERROR; } import_failed: { GST_ERROR_OBJECT (pool, "failed to import dmabuf"); return GST_FLOW_ERROR; } } static GstFlowReturn gst_v4l2_buffer_pool_prepare_buffer (GstV4l2BufferPool * pool, GstBuffer * dest, GstBuffer * src) { GstFlowReturn ret = GST_FLOW_OK; gboolean own_src = FALSE; if (src == NULL) { if (pool->other_pool == NULL) { GST_ERROR_OBJECT (pool, "can't prepare buffer, source buffer missing"); return GST_FLOW_ERROR; } ret = gst_buffer_pool_acquire_buffer (pool->other_pool, &src, NULL); if (ret != GST_FLOW_OK) { GST_ERROR_OBJECT (pool, "failed to acquire buffer from downstream pool"); goto done; } own_src = TRUE; } switch (pool->obj->mode) { case GST_V4L2_IO_MMAP: case GST_V4L2_IO_DMABUF: ret = gst_v4l2_buffer_pool_copy_buffer (pool, dest, src); break; case GST_V4L2_IO_USERPTR: ret = gst_v4l2_buffer_pool_import_userptr (pool, dest, src); break; case GST_V4L2_IO_DMABUF_IMPORT: ret = gst_v4l2_buffer_pool_import_dmabuf (pool, dest, src); break; default: break; } if (own_src) gst_buffer_unref (src); done: return ret; } static GstFlowReturn gst_v4l2_buffer_pool_alloc_buffer (GstBufferPool * bpool, GstBuffer ** buffer, GstBufferPoolAcquireParams * params) { GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool); GstV4l2MemoryGroup *group = NULL; GstBuffer *newbuf = NULL; GstV4l2Object *obj; GstVideoInfo *info; obj = pool->obj; info = &obj->info; switch (obj->mode) { case GST_V4L2_IO_RW: newbuf = gst_buffer_new_allocate (pool->allocator, pool->size, &pool->params); break; case GST_V4L2_IO_MMAP: group = gst_v4l2_allocator_alloc_mmap (pool->vallocator); break; case GST_V4L2_IO_DMABUF: group = gst_v4l2_allocator_alloc_dmabuf (pool->vallocator, pool->allocator); break; case GST_V4L2_IO_USERPTR: group = gst_v4l2_allocator_alloc_userptr (pool->vallocator); break; case GST_V4L2_IO_DMABUF_IMPORT: group = gst_v4l2_allocator_alloc_dmabufin (pool->vallocator); break; default: newbuf = NULL; g_assert_not_reached (); break; } if (group != NULL) { gint i; newbuf = gst_buffer_new (); for (i = 0; i < group->n_mem; i++) gst_buffer_append_memory (newbuf, group->mem[i]); if (g_atomic_int_get (&pool->buffer_state[group->buffer.index])) { GST_WARNING_OBJECT (pool, "newly allocated buffer %u is not free", group->buffer.index); } } else if (newbuf == NULL) { goto allocation_failed; } /* add metadata to raw video buffers */ if (pool->add_videometa) { GstVideoMeta *videometa = gst_buffer_add_video_meta_full (newbuf, GST_VIDEO_FRAME_FLAG_NONE, GST_VIDEO_INFO_FORMAT (info), GST_VIDEO_INFO_WIDTH (info), GST_VIDEO_INFO_HEIGHT (info), GST_VIDEO_INFO_N_PLANES (info), info->offset, info->stride); if (videometa) gst_video_meta_set_alignment (videometa, obj->align); } *buffer = newbuf; return GST_FLOW_OK; /* ERRORS */ allocation_failed: { GST_ERROR_OBJECT (pool, "failed to allocate buffer"); return GST_FLOW_ERROR; } } static gboolean gst_v4l2_buffer_pool_set_config (GstBufferPool * bpool, GstStructure * config) { GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool); GstV4l2Object *obj = pool->obj; GstCaps *caps; guint size, min_buffers, max_buffers; GstAllocator *allocator; GstAllocationParams params; gboolean can_allocate = FALSE; gboolean updated = FALSE; gboolean ret; pool->add_videometa = gst_buffer_pool_config_has_option (config, GST_BUFFER_POOL_OPTION_VIDEO_META); /* parse the config and keep around */ if (!gst_buffer_pool_config_get_params (config, &caps, &size, &min_buffers, &max_buffers)) goto wrong_config; if (!gst_buffer_pool_config_get_allocator (config, &allocator, ¶ms)) goto wrong_config; GST_DEBUG_OBJECT (pool, "config %" GST_PTR_FORMAT, config); if (pool->allocator) gst_object_unref (pool->allocator); pool->allocator = NULL; switch (obj->mode) { case GST_V4L2_IO_DMABUF: pool->allocator = gst_dmabuf_allocator_new (); can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, MMAP); break; case GST_V4L2_IO_MMAP: can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, MMAP); break; case GST_V4L2_IO_USERPTR: can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, USERPTR); break; case GST_V4L2_IO_DMABUF_IMPORT: can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, DMABUF); break; case GST_V4L2_IO_RW: if (allocator) pool->allocator = g_object_ref (allocator); pool->params = params; /* No need to change the configuration */ goto done; break; default: g_assert_not_reached (); break; } /* libv4l2 conversion code does not handle CREATE_BUFS, and may lead to * instability and crash, disable it for now */ if (can_allocate && obj->fmtdesc->flags & V4L2_FMT_FLAG_EMULATED) { GST_WARNING_OBJECT (pool, "libv4l2 converter detected, disabling CREATE_BUFS"); can_allocate = FALSE; GST_OBJECT_FLAG_UNSET (pool->vallocator, GST_V4L2_ALLOCATOR_FLAG_MMAP_CREATE_BUFS | GST_V4L2_ALLOCATOR_FLAG_USERPTR_CREATE_BUFS | GST_V4L2_ALLOCATOR_FLAG_DMABUF_CREATE_BUFS); } if (min_buffers < GST_V4L2_MIN_BUFFERS (obj)) { updated = TRUE; min_buffers = GST_V4L2_MIN_BUFFERS (obj); GST_INFO_OBJECT (pool, "increasing minimum buffers to %u", min_buffers); } /* respect driver requirements */ if (min_buffers < obj->min_buffers) { updated = TRUE; min_buffers = obj->min_buffers; GST_INFO_OBJECT (pool, "increasing minimum buffers to %u", min_buffers); } if (max_buffers > VIDEO_MAX_FRAME || max_buffers == 0) { updated = TRUE; max_buffers = VIDEO_MAX_FRAME; GST_INFO_OBJECT (pool, "reducing maximum buffers to %u", max_buffers); } if (min_buffers > max_buffers) { updated = TRUE; min_buffers = max_buffers; GST_INFO_OBJECT (pool, "reducing minimum buffers to %u", min_buffers); } else if (min_buffers != max_buffers) { if (!can_allocate) { updated = TRUE; max_buffers = min_buffers; GST_INFO_OBJECT (pool, "can't allocate, setting maximum to minimum"); } } if (!pool->add_videometa && obj->need_video_meta) { GST_INFO_OBJECT (pool, "adding needed video meta"); updated = TRUE; gst_buffer_pool_config_add_option (config, GST_BUFFER_POOL_OPTION_VIDEO_META); } /* Always update the config to ensure the configured size matches */ gst_buffer_pool_config_set_params (config, caps, obj->info.size, min_buffers, max_buffers); /* keep a GstVideoInfo with defaults for the when we need to copy */ gst_video_info_from_caps (&pool->caps_info, caps); done: ret = GST_BUFFER_POOL_CLASS (parent_class)->set_config (bpool, config); /* If anything was changed documentation recommend to return FALSE */ return !updated && ret; /* ERRORS */ wrong_config: { GST_ERROR_OBJECT (pool, "invalid config %" GST_PTR_FORMAT, config); return FALSE; } } static GstFlowReturn gst_v4l2_buffer_pool_resurrect_buffer (GstV4l2BufferPool * pool) { GstBufferPoolAcquireParams params = { 0 }; GstBuffer *buffer = NULL; GstFlowReturn ret; GST_DEBUG_OBJECT (pool, "A buffer was lost, reallocating it"); /* block recursive calls to this function */ g_signal_handler_block (pool->vallocator, pool->group_released_handler); params.flags = (GstBufferPoolAcquireFlags) GST_V4L2_BUFFER_POOL_ACQUIRE_FLAG_RESURRECT | GST_BUFFER_POOL_ACQUIRE_FLAG_DONTWAIT; ret = gst_buffer_pool_acquire_buffer (GST_BUFFER_POOL (pool), &buffer, ¶ms); if (ret == GST_FLOW_OK) gst_buffer_unref (buffer); g_signal_handler_unblock (pool->vallocator, pool->group_released_handler); return ret; } static gboolean gst_v4l2_buffer_pool_streamon (GstV4l2BufferPool * pool) { GstV4l2Object *obj = pool->obj; if (pool->streaming) return TRUE; switch (obj->mode) { case GST_V4L2_IO_MMAP: case GST_V4L2_IO_USERPTR: case GST_V4L2_IO_DMABUF: case GST_V4L2_IO_DMABUF_IMPORT: if (!V4L2_TYPE_IS_OUTPUT (pool->obj->type)) { guint num_queued; guint i, n = 0; GST_OBJECT_LOCK (pool); num_queued = g_atomic_int_get (&pool->num_queued); if (num_queued < pool->num_allocated) n = pool->num_allocated - num_queued; GST_OBJECT_UNLOCK (pool); /* For captures, we need to enqueue buffers before we start streaming, * so the driver don't underflow immediately. As we have put then back * into the base class queue, resurrect them, then releasing will queue * them back. */ for (i = 0; i < n; i++) gst_v4l2_buffer_pool_resurrect_buffer (pool); } if (obj->ioctl (pool->video_fd, VIDIOC_STREAMON, &obj->type) < 0) goto streamon_failed; pool->streaming = TRUE; GST_DEBUG_OBJECT (pool, "Started streaming"); break; default: break; } return TRUE; streamon_failed: { GST_ERROR_OBJECT (pool, "error with STREAMON %d (%s)", errno, g_strerror (errno)); return FALSE; } } /* Call with streamlock held, or when streaming threads are down */ static void gst_v4l2_buffer_pool_streamoff (GstV4l2BufferPool * pool) { GstBufferPoolClass *pclass = GST_BUFFER_POOL_CLASS (parent_class); GstV4l2Object *obj = pool->obj; gint i; if (!pool->streaming) return; switch (obj->mode) { case GST_V4L2_IO_MMAP: case GST_V4L2_IO_USERPTR: case GST_V4L2_IO_DMABUF: case GST_V4L2_IO_DMABUF_IMPORT: if (obj->ioctl (pool->video_fd, VIDIOC_STREAMOFF, &obj->type) < 0) GST_WARNING_OBJECT (pool, "STREAMOFF failed with errno %d (%s)", errno, g_strerror (errno)); pool->streaming = FALSE; GST_DEBUG_OBJECT (pool, "Stopped streaming"); if (pool->vallocator) gst_v4l2_allocator_flush (pool->vallocator); break; default: break; } for (i = 0; i < VIDEO_MAX_FRAME; i++) { gint old_buffer_state = g_atomic_int_and (&pool->buffer_state[i], ~BUFFER_STATE_QUEUED); if ((old_buffer_state & BUFFER_STATE_QUEUED) && pool->buffers[i]) { GstBuffer *buffer = pool->buffers[i]; GstBufferPool *bpool = GST_BUFFER_POOL (pool); pool->buffers[i] = NULL; if (!(old_buffer_state & BUFFER_STATE_OUTSTANDING)) { if (V4L2_TYPE_IS_OUTPUT (pool->obj->type)) gst_v4l2_buffer_pool_complete_release_buffer (bpool, buffer, FALSE); else /* Don't re-enqueue capture buffer on stop */ pclass->release_buffer (bpool, buffer); } g_atomic_int_add (&pool->num_queued, -1); } } } static gboolean gst_v4l2_buffer_pool_start (GstBufferPool * bpool) { GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool); GstBufferPoolClass *pclass = GST_BUFFER_POOL_CLASS (parent_class); GstV4l2Object *obj = pool->obj; GstStructure *config; GstCaps *caps; guint size, min_buffers, max_buffers; guint max_latency, min_latency, copy_threshold = 0; gboolean can_allocate = FALSE, ret = TRUE; GST_DEBUG_OBJECT (pool, "activating pool"); if (pool->other_pool) { GstBuffer *buffer; if (!gst_buffer_pool_set_active (pool->other_pool, TRUE)) goto other_pool_failed; if (gst_buffer_pool_acquire_buffer (pool->other_pool, &buffer, NULL) != GST_FLOW_OK) goto other_pool_failed; if (!gst_v4l2_object_try_import (obj, buffer)) { gst_buffer_unref (buffer); goto cannot_import; } gst_buffer_unref (buffer); } config = gst_buffer_pool_get_config (bpool); if (!gst_buffer_pool_config_get_params (config, &caps, &size, &min_buffers, &max_buffers)) goto wrong_config; min_latency = MAX (GST_V4L2_MIN_BUFFERS (obj), obj->min_buffers); switch (obj->mode) { case GST_V4L2_IO_RW: can_allocate = TRUE; #ifdef HAVE_LIBV4L2 /* This workaround a unfixable bug in libv4l2 when RW is emulated on top * of MMAP. In this case, the first read initialize the queues, but the * poll before that will always fail. Doing an empty read, forces the * queue to be initialized now. We only do this if we have a streaming * driver. */ if (obj->device_caps & V4L2_CAP_STREAMING) obj->read (obj->video_fd, NULL, 0); #endif break; case GST_V4L2_IO_DMABUF: case GST_V4L2_IO_MMAP: { guint count; can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, MMAP); /* first, lets request buffers, and see how many we can get: */ GST_DEBUG_OBJECT (pool, "requesting %d MMAP buffers", min_buffers); count = gst_v4l2_allocator_start (pool->vallocator, min_buffers, V4L2_MEMORY_MMAP); pool->num_allocated = count; if (count < GST_V4L2_MIN_BUFFERS (obj)) { min_buffers = count; goto no_buffers; } /* V4L2 buffer pool are often very limited in the amount of buffers it * can offer. The copy_threshold will workaround this limitation by * falling back to copy if the pipeline needed more buffers. This also * prevent having to do REQBUFS(N)/REQBUFS(0) every time configure is * called. */ if (count != min_buffers || pool->enable_copy_threshold) { GST_WARNING_OBJECT (pool, "Uncertain or not enough buffers, enabling copy threshold"); min_buffers = count; copy_threshold = min_latency; } break; } case GST_V4L2_IO_USERPTR: { guint count; can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, USERPTR); GST_DEBUG_OBJECT (pool, "requesting %d USERPTR buffers", min_buffers); count = gst_v4l2_allocator_start (pool->vallocator, min_buffers, V4L2_MEMORY_USERPTR); pool->num_allocated = count; /* There is no rational to not get what we asked */ if (count < min_buffers) { min_buffers = count; goto no_buffers; } min_buffers = count; break; } case GST_V4L2_IO_DMABUF_IMPORT: { guint count; can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, DMABUF); GST_DEBUG_OBJECT (pool, "requesting %d DMABUF buffers", min_buffers); count = gst_v4l2_allocator_start (pool->vallocator, min_buffers, V4L2_MEMORY_DMABUF); pool->num_allocated = count; /* There is no rational to not get what we asked */ if (count < min_buffers) { min_buffers = count; goto no_buffers; } min_buffers = count; break; } default: min_buffers = 0; copy_threshold = 0; g_assert_not_reached (); break; } if (can_allocate) max_latency = max_buffers; else max_latency = min_buffers; pool->size = size; pool->copy_threshold = copy_threshold; pool->max_latency = max_latency; pool->min_latency = min_latency; pool->num_queued = 0; if (max_buffers != 0 && max_buffers < min_buffers) max_buffers = min_buffers; gst_buffer_pool_config_set_params (config, caps, size, min_buffers, max_buffers); pclass->set_config (bpool, config); gst_structure_free (config); /* now, allocate the buffers: */ if (!pclass->start (bpool)) goto start_failed; if (!V4L2_TYPE_IS_OUTPUT (obj->type)) { if (g_atomic_int_get (&pool->num_queued) < pool->num_allocated) goto queue_failed; pool->group_released_handler = g_signal_connect_swapped (pool->vallocator, "group-released", G_CALLBACK (gst_v4l2_buffer_pool_resurrect_buffer), pool); ret = gst_v4l2_buffer_pool_streamon (pool); } return ret; /* ERRORS */ wrong_config: { GST_ERROR_OBJECT (pool, "invalid config %" GST_PTR_FORMAT, config); gst_structure_free (config); return FALSE; } no_buffers: { GST_ERROR_OBJECT (pool, "we received %d buffer from device '%s', we want at least %d", min_buffers, obj->videodev, GST_V4L2_MIN_BUFFERS (obj)); gst_structure_free (config); return FALSE; } start_failed: { GST_ERROR_OBJECT (pool, "allocate failed"); return FALSE; } other_pool_failed: { GST_ERROR_OBJECT (pool, "failed to activate the other pool %" GST_PTR_FORMAT, pool->other_pool); return FALSE; } queue_failed: { GST_ERROR_OBJECT (pool, "failed to queue buffers into the capture queue"); return FALSE; } cannot_import: { GST_ERROR_OBJECT (pool, "cannot import buffers from downstream pool"); return FALSE; } } static gboolean gst_v4l2_buffer_pool_vallocator_stop (GstV4l2BufferPool * pool) { GstV4l2Return vret; if (!pool->vallocator) return TRUE; vret = gst_v4l2_allocator_stop (pool->vallocator); if (vret == GST_V4L2_BUSY) GST_WARNING_OBJECT (pool, "some buffers are still outstanding"); return (vret == GST_V4L2_OK); } static gboolean gst_v4l2_buffer_pool_stop (GstBufferPool * bpool) { GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool); gboolean ret; GST_DEBUG_OBJECT (pool, "stopping pool"); if (pool->group_released_handler > 0) { g_signal_handler_disconnect (pool->vallocator, pool->group_released_handler); pool->group_released_handler = 0; } if (pool->other_pool) { gst_buffer_pool_set_active (pool->other_pool, FALSE); gst_object_unref (pool->other_pool); pool->other_pool = NULL; } if (!pool->orphaned) gst_v4l2_buffer_pool_streamoff (pool); ret = GST_BUFFER_POOL_CLASS (parent_class)->stop (bpool); if (ret) ret = gst_v4l2_buffer_pool_vallocator_stop (pool); return ret; } gboolean gst_v4l2_buffer_pool_orphan (GstV4l2Object * v4l2object) { GstBufferPool *bpool = gst_v4l2_object_get_buffer_pool (v4l2object); GstV4l2BufferPool *pool; gboolean ret; /* Nothing to do if there is no pool */ if (!bpool) return TRUE; pool = GST_V4L2_BUFFER_POOL (bpool); if (pool->orphaned != FALSE || !GST_V4L2_ALLOCATOR_CAN_ORPHAN_BUFS (pool->vallocator) || g_getenv ("GST_V4L2_FORCE_DRAIN")) { gst_object_unref (bpool); return FALSE; } GST_DEBUG_OBJECT (pool, "orphaning pool"); gst_buffer_pool_set_active (bpool, FALSE); /* We lock to prevent racing with a return buffer in QBuf, and has a * workaround of not being able to use the pool hidden activation lock. */ GST_OBJECT_LOCK (pool); gst_v4l2_buffer_pool_streamoff (pool); ret = gst_v4l2_allocator_orphan (pool->vallocator); if (ret) pool->orphaned = TRUE; GST_OBJECT_UNLOCK (pool); if (ret) { GstBufferPool *old_pool; GST_OBJECT_LOCK (v4l2object->element); old_pool = v4l2object->pool; v4l2object->pool = NULL; GST_OBJECT_UNLOCK (v4l2object->element); if (old_pool) gst_object_unref (old_pool); } gst_object_unref (bpool); return ret; } static void gst_v4l2_buffer_pool_flush_start (GstBufferPool * bpool) { GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool); GST_DEBUG_OBJECT (pool, "start flushing"); gst_poll_set_flushing (pool->obj->poll, TRUE); GST_OBJECT_LOCK (pool); pool->empty = FALSE; g_cond_broadcast (&pool->empty_cond); GST_OBJECT_UNLOCK (pool); if (pool->other_pool && gst_buffer_pool_is_active (pool->other_pool)) gst_buffer_pool_set_flushing (pool->other_pool, TRUE); } static void gst_v4l2_buffer_pool_flush_stop (GstBufferPool * bpool) { GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool); GST_DEBUG_OBJECT (pool, "stop flushing"); if (pool->other_pool && gst_buffer_pool_is_active (pool->other_pool)) gst_buffer_pool_set_flushing (pool->other_pool, FALSE); gst_poll_set_flushing (pool->obj->poll, FALSE); } static GstFlowReturn gst_v4l2_buffer_pool_poll (GstV4l2BufferPool * pool, gboolean wait) { GstClockTime timeout; if (wait) timeout = GST_CLOCK_TIME_NONE; else timeout = 0; /* In RW mode there is no queue, hence no need to wait while the queue is * empty */ if (pool->obj->mode != GST_V4L2_IO_RW) { GST_OBJECT_LOCK (pool); if (!wait && pool->empty) { GST_OBJECT_UNLOCK (pool); return GST_V4L2_FLOW_LAST_BUFFER; } while (pool->empty) g_cond_wait (&pool->empty_cond, GST_OBJECT_GET_LOCK (pool)); GST_OBJECT_UNLOCK (pool); } if (!pool->obj->can_poll_device) { if (wait) return GST_FLOW_OK; else return GST_V4L2_FLOW_LAST_BUFFER; } return gst_v4l2_object_poll (pool->obj, timeout); } static GstFlowReturn gst_v4l2_buffer_pool_qbuf (GstV4l2BufferPool * pool, GstBuffer * buf, GstV4l2MemoryGroup * group, guint32 * frame_number) { const GstV4l2Object *obj = pool->obj; gint old_buffer_state; gint index; GST_OBJECT_LOCK (pool); index = group->buffer.index; old_buffer_state = g_atomic_int_or (&pool->buffer_state[index], BUFFER_STATE_QUEUED); if (old_buffer_state & BUFFER_STATE_QUEUED) goto already_queued; GST_LOG_OBJECT (pool, "queuing buffer %i, previous-state = %i", index, old_buffer_state); if (V4L2_TYPE_IS_OUTPUT (obj->type)) { enum v4l2_field field; /* Buffer field is the same as the one defined in format */ if (V4L2_TYPE_IS_MULTIPLANAR (obj->type)) field = obj->format.fmt.pix_mp.field; else field = obj->format.fmt.pix.field; group->buffer.field = field; } if (frame_number) { group->buffer.timestamp.tv_sec = *frame_number; group->buffer.timestamp.tv_usec = 0; } else { if (GST_BUFFER_TIMESTAMP_IS_VALID (buf)) { GstClockTime timestamp = GST_BUFFER_TIMESTAMP (buf); GST_TIME_TO_TIMEVAL (timestamp, group->buffer.timestamp); } else { group->buffer.timestamp.tv_sec = -1; group->buffer.timestamp.tv_usec = -1; } } /* If the pool was orphaned, don't try to queue any returned buffers. * This is done with the objet lock in order to synchronize with * orphaning. */ if (pool->orphaned) goto was_orphaned; g_atomic_int_inc (&pool->num_queued); pool->buffers[index] = buf; if (!gst_v4l2_allocator_qbuf (pool->vallocator, group)) goto queue_failed; pool->empty = FALSE; g_cond_signal (&pool->empty_cond); GST_OBJECT_UNLOCK (pool); return GST_FLOW_OK; already_queued: { GST_ERROR_OBJECT (pool, "the buffer %i was already queued", index); GST_OBJECT_UNLOCK (pool); return GST_FLOW_ERROR; } was_orphaned: { GST_DEBUG_OBJECT (pool, "pool was orphaned, not queuing back buffer."); GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_TAG_MEMORY); g_atomic_int_and (&pool->buffer_state[index], ~BUFFER_STATE_QUEUED); GST_OBJECT_UNLOCK (pool); return GST_FLOW_FLUSHING; } queue_failed: { GST_ERROR_OBJECT (pool, "could not queue a buffer %i", index); /* Mark broken buffer to the allocator */ GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_TAG_MEMORY); g_atomic_int_add (&pool->num_queued, -1); pool->buffers[index] = NULL; g_atomic_int_and (&pool->buffer_state[index], ~BUFFER_STATE_QUEUED); GST_OBJECT_UNLOCK (pool); return GST_FLOW_ERROR; } } static GstFlowReturn gst_v4l2_buffer_pool_dqbuf (GstV4l2BufferPool * pool, GstBuffer ** buffer, gboolean * outstanding, gboolean wait) { GstBufferPool *bpool = GST_BUFFER_POOL_CAST (pool); GstFlowReturn res; GstBuffer *outbuf = NULL; GstV4l2Object *obj = pool->obj; GstClockTime timestamp; GstV4l2MemoryGroup *group; const GstVideoInfo *info = &obj->info; gint i; gint old_buffer_state; if ((res = gst_v4l2_buffer_pool_poll (pool, wait)) < GST_FLOW_OK) goto poll_failed; if (res == GST_V4L2_FLOW_LAST_BUFFER) { GST_LOG_OBJECT (pool, "nothing to dequeue"); goto done; } if (res == GST_V4L2_FLOW_RESOLUTION_CHANGE) { GST_INFO_OBJECT (pool, "Resolution change detected."); goto done; } GST_LOG_OBJECT (pool, "dequeueing a buffer"); res = gst_v4l2_allocator_dqbuf (pool->vallocator, &group); if (res == GST_V4L2_FLOW_LAST_BUFFER) goto eos; if (res != GST_FLOW_OK) goto dqbuf_failed; old_buffer_state = g_atomic_int_and (&pool->buffer_state[group->buffer.index], ~BUFFER_STATE_QUEUED); if (!(old_buffer_state & BUFFER_STATE_QUEUED)) goto no_buffer; if (outstanding) { *outstanding = (old_buffer_state & BUFFER_STATE_OUTSTANDING) != 0; } else if (old_buffer_state & BUFFER_STATE_OUTSTANDING) { GST_WARNING_OBJECT (pool, "unexpected outstanding buffer %u", group->buffer.index); } outbuf = pool->buffers[group->buffer.index]; if (outbuf == NULL) goto no_buffer; pool->buffers[group->buffer.index] = NULL; if (g_atomic_int_dec_and_test (&pool->num_queued)) { GST_OBJECT_LOCK (pool); pool->empty = TRUE; GST_OBJECT_UNLOCK (pool); } if (group->buffer.flags & V4L2_BUF_FLAG_LAST && group->planes[0].bytesused == 0) { GST_DEBUG_OBJECT (pool, "Empty last buffer, signalling eos."); gst_v4l2_buffer_pool_complete_release_buffer (bpool, outbuf, FALSE); *buffer = NULL; goto eos; } timestamp = GST_TIMEVAL_TO_TIME (group->buffer.timestamp); for (i = 0; i < group->n_mem; i++) { const GstVideoFormatInfo *finfo = info->finfo; GST_LOG_OBJECT (pool, "dequeued buffer %p seq:%d (ix=%d), mem %p used %d, plane=%d, flags %08x, ts %" GST_TIME_FORMAT ", pool-queued=%d, buffer=%p, previous-state=%i", outbuf, group->buffer.sequence, group->buffer.index, group->mem[i], group->planes[i].bytesused, i, group->buffer.flags, GST_TIME_ARGS (timestamp), pool->num_queued, outbuf, old_buffer_state); if (GST_VIDEO_INFO_FORMAT (&pool->caps_info) == GST_VIDEO_FORMAT_ENCODED) break; if (obj->type == V4L2_BUF_TYPE_VIDEO_CAPTURE || obj->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE) { /* Ensure our offset matches the expected plane size, or image size if * there is only one memory */ if (group->n_mem == 1) { gst_memory_resize (group->mem[0], 0, info->size + info->offset[0]); break; } if (!GST_VIDEO_FORMAT_INFO_IS_TILED (finfo)) gst_memory_resize (group->mem[i], 0, obj->plane_size[i]); } } /* Ignore timestamp and field for OUTPUT device */ if (V4L2_TYPE_IS_OUTPUT (obj->type)) goto done; /* Check for driver bug in reporting feild */ if (group->buffer.field == V4L2_FIELD_ANY) { /* Only warn once to avoid the spamming */ #ifndef GST_DISABLE_GST_DEBUG if (!pool->has_warned_on_buggy_field) { pool->has_warned_on_buggy_field = TRUE; GST_WARNING_OBJECT (pool, "Driver should never set v4l2_buffer.field to ANY"); } #endif /* Use the value from the format (works for UVC bug) */ group->buffer.field = obj->format.fmt.pix.field; /* If driver also has buggy S_FMT, assume progressive */ if (group->buffer.field == V4L2_FIELD_ANY) { #ifndef GST_DISABLE_GST_DEBUG if (!pool->has_warned_on_buggy_field) { pool->has_warned_on_buggy_field = TRUE; GST_WARNING_OBJECT (pool, "Driver should never set v4l2_format.pix.field to ANY"); } #endif group->buffer.field = V4L2_FIELD_NONE; } } /* set top/bottom field first if v4l2_buffer has the information */ switch (group->buffer.field) { case V4L2_FIELD_NONE: GST_BUFFER_FLAG_UNSET (outbuf, GST_VIDEO_BUFFER_FLAG_INTERLACED); GST_BUFFER_FLAG_UNSET (outbuf, GST_VIDEO_BUFFER_FLAG_TFF); break; case V4L2_FIELD_TOP: GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_INTERLACED); GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_TOP_FIELD); break; case V4L2_FIELD_BOTTOM: GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_INTERLACED); GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_BOTTOM_FIELD); break; case V4L2_FIELD_INTERLACED_TB: GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_INTERLACED); GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_TFF); break; case V4L2_FIELD_INTERLACED_BT: GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_INTERLACED); GST_BUFFER_FLAG_UNSET (outbuf, GST_VIDEO_BUFFER_FLAG_TFF); break; case V4L2_FIELD_INTERLACED: GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_INTERLACED); if (obj->tv_norm == V4L2_STD_NTSC_M || obj->tv_norm == V4L2_STD_NTSC_M_JP || obj->tv_norm == V4L2_STD_NTSC_M_KR) { GST_BUFFER_FLAG_UNSET (outbuf, GST_VIDEO_BUFFER_FLAG_TFF); } else { GST_BUFFER_FLAG_SET (outbuf, GST_VIDEO_BUFFER_FLAG_TFF); } break; default: GST_BUFFER_FLAG_UNSET (outbuf, GST_VIDEO_BUFFER_FLAG_INTERLACED); GST_BUFFER_FLAG_UNSET (outbuf, GST_VIDEO_BUFFER_FLAG_TFF); GST_FIXME_OBJECT (pool, "Unhandled enum v4l2_field %d - treating as progressive", group->buffer.field); break; } if (!gst_v4l2_object_is_raw (obj)) { if ((group->buffer.flags & V4L2_BUF_FLAG_KEYFRAME) || GST_V4L2_PIXELFORMAT (obj) == V4L2_PIX_FMT_MJPEG || GST_V4L2_PIXELFORMAT (obj) == V4L2_PIX_FMT_JPEG || GST_V4L2_PIXELFORMAT (obj) == V4L2_PIX_FMT_PJPG) GST_BUFFER_FLAG_UNSET (outbuf, GST_BUFFER_FLAG_DELTA_UNIT); else GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DELTA_UNIT); } if (group->buffer.flags & V4L2_BUF_FLAG_ERROR) GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_CORRUPTED); GST_BUFFER_TIMESTAMP (outbuf) = timestamp; GST_BUFFER_OFFSET (outbuf) = group->buffer.sequence; GST_BUFFER_OFFSET_END (outbuf) = group->buffer.sequence + 1; done: *buffer = outbuf; return res; /* ERRORS */ poll_failed: { GST_DEBUG_OBJECT (pool, "poll error %s", gst_flow_get_name (res)); return res; } eos: { return GST_V4L2_FLOW_LAST_BUFFER; } dqbuf_failed: { return GST_FLOW_ERROR; } no_buffer: { GST_ERROR_OBJECT (pool, "No free buffer found in the pool at index %d.", group->buffer.index); return GST_FLOW_ERROR; } } static GstFlowReturn gst_v4l2_buffer_pool_acquire_buffer (GstBufferPool * bpool, GstBuffer ** buffer, GstBufferPoolAcquireParams * params) { GstFlowReturn ret; GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool); GstBufferPoolClass *pclass = GST_BUFFER_POOL_CLASS (parent_class); GstV4l2Object *obj = pool->obj; GST_DEBUG_OBJECT (pool, "acquire"); /* If this is being called to resurrect a lost buffer */ if (params && params->flags & GST_V4L2_BUFFER_POOL_ACQUIRE_FLAG_RESURRECT) { ret = pclass->acquire_buffer (bpool, buffer, params); goto done; } switch (obj->type) { case V4L2_BUF_TYPE_VIDEO_CAPTURE: case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE: /* capture, This function should return a buffer with new captured data */ switch (obj->mode) { case GST_V4L2_IO_RW: { /* take empty buffer from the pool */ ret = pclass->acquire_buffer (bpool, buffer, params); break; } case GST_V4L2_IO_DMABUF: case GST_V4L2_IO_MMAP: case GST_V4L2_IO_USERPTR: case GST_V4L2_IO_DMABUF_IMPORT: { /* just dequeue a buffer, we basically use the queue of v4l2 as the * storage for our buffers. This function does poll first so we can * interrupt it fine. */ ret = gst_v4l2_buffer_pool_dqbuf (pool, buffer, NULL, TRUE); break; } default: ret = GST_FLOW_ERROR; g_assert_not_reached (); break; } break; case V4L2_BUF_TYPE_VIDEO_OUTPUT: case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE: /* playback, This function should return an empty buffer */ switch (obj->mode) { case GST_V4L2_IO_RW: /* get an empty buffer */ ret = pclass->acquire_buffer (bpool, buffer, params); break; case GST_V4L2_IO_MMAP: case GST_V4L2_IO_DMABUF: case GST_V4L2_IO_USERPTR: case GST_V4L2_IO_DMABUF_IMPORT: /* get a free unqueued buffer */ ret = pclass->acquire_buffer (bpool, buffer, params); break; default: ret = GST_FLOW_ERROR; g_assert_not_reached (); break; } break; default: ret = GST_FLOW_ERROR; g_assert_not_reached (); break; } done: /* Mark buffer as outstanding */ if (ret == GST_FLOW_OK) { GstV4l2MemoryGroup *group; if (gst_v4l2_is_buffer_valid (*buffer, &group, TRUE)) { GST_LOG_OBJECT (pool, "mark buffer %u outstanding", group->buffer.index); g_atomic_int_or (&pool->buffer_state[group->buffer.index], BUFFER_STATE_OUTSTANDING); } } return ret; } /* * Completes a release buffer operation * * Before calling this function: * - The buffer state (if applicable) must have already been updated. * - The buffer must not be outstanding. * - The "queued" argument contains whether the buffer is currently queued. */ static void gst_v4l2_buffer_pool_complete_release_buffer (GstBufferPool * bpool, GstBuffer * buffer, gboolean queued) { GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool); GstBufferPoolClass *pclass = GST_BUFFER_POOL_CLASS (parent_class); GstV4l2Object *obj = pool->obj; GST_DEBUG_OBJECT (pool, "complete release buffer %p (queued = %s)", buffer, queued ? "yes" : "no"); switch (obj->type) { case V4L2_BUF_TYPE_VIDEO_CAPTURE: case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE: /* capture, put the buffer back in the queue so that we can refill it * later. */ if (queued) { GST_WARNING_OBJECT (pool, "capture buffer %p was release while still queued", buffer); } switch (obj->mode) { case GST_V4L2_IO_RW: /* release back in the pool */ pclass->release_buffer (bpool, buffer); break; case GST_V4L2_IO_DMABUF: case GST_V4L2_IO_MMAP: case GST_V4L2_IO_USERPTR: case GST_V4L2_IO_DMABUF_IMPORT: { GstV4l2MemoryGroup *group; if (gst_v4l2_is_buffer_valid (buffer, &group, TRUE)) { GstFlowReturn ret = GST_FLOW_OK; gst_v4l2_allocator_reset_group (pool->vallocator, group); /* queue back in the device */ if (pool->other_pool) ret = gst_v4l2_buffer_pool_prepare_buffer (pool, buffer, NULL); if (ret != GST_FLOW_OK || gst_v4l2_buffer_pool_qbuf (pool, buffer, group, NULL) != GST_FLOW_OK) pclass->release_buffer (bpool, buffer); } else { /* Simply release invalid/modified buffer, the allocator will * give it back later */ GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY); pclass->release_buffer (bpool, buffer); } break; } default: g_assert_not_reached (); break; } break; case V4L2_BUF_TYPE_VIDEO_OUTPUT: case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE: switch (obj->mode) { case GST_V4L2_IO_RW: /* release back in the pool */ pclass->release_buffer (bpool, buffer); break; case GST_V4L2_IO_MMAP: case GST_V4L2_IO_DMABUF: case GST_V4L2_IO_USERPTR: case GST_V4L2_IO_DMABUF_IMPORT: { GstV4l2MemoryGroup *group; guint index; if (!gst_v4l2_is_buffer_valid (buffer, &group, TRUE)) { /* Simply release invalid/modified buffer, the allocator will * give it back later */ GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY); pclass->release_buffer (bpool, buffer); break; } index = group->buffer.index; if (!queued) { GST_LOG_OBJECT (pool, "buffer %u not queued, putting on free list", index); /* Remove qdata, this will unmap any map data in userptr */ gst_mini_object_set_qdata (GST_MINI_OBJECT (buffer), GST_V4L2_IMPORT_QUARK, NULL, NULL); /* reset to default size */ gst_v4l2_allocator_reset_group (pool->vallocator, group); /* playback, put the buffer back in the queue to refill later. */ pclass->release_buffer (bpool, buffer); } else { /* the buffer is queued in the device but maybe not played yet. We just * leave it there and not make it available for future calls to acquire * for now. The buffer will be dequeued and reused later. */ GST_LOG_OBJECT (pool, "buffer %u is queued", index); } break; } default: g_assert_not_reached (); break; } break; default: g_assert_not_reached (); break; } } static void gst_v4l2_buffer_pool_release_buffer (GstBufferPool * bpool, GstBuffer * buffer) { GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool); GstV4l2MemoryGroup *group; gboolean queued = FALSE; if (gst_v4l2_is_buffer_valid (buffer, &group, TRUE)) { gint old_buffer_state = g_atomic_int_and (&pool->buffer_state[group->buffer.index], ~BUFFER_STATE_OUTSTANDING); queued = (old_buffer_state & BUFFER_STATE_QUEUED) != 0; GST_LOG_OBJECT (pool, "mark buffer %u not outstanding", group->buffer.index); } gst_v4l2_buffer_pool_complete_release_buffer (bpool, buffer, queued); } static void gst_v4l2_buffer_pool_dispose (GObject * object) { GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (object); if (pool->vallocator) gst_object_unref (pool->vallocator); pool->vallocator = NULL; if (pool->allocator) gst_object_unref (pool->allocator); pool->allocator = NULL; if (pool->other_pool) gst_object_unref (pool->other_pool); pool->other_pool = NULL; G_OBJECT_CLASS (parent_class)->dispose (object); } static void gst_v4l2_buffer_pool_finalize (GObject * object) { GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (object); if (pool->video_fd >= 0) pool->obj->close (pool->video_fd); /* This can't be done in dispose method because we must not set pointer * to NULL as it is part of the v4l2object and dispose could be called * multiple times */ gst_object_unref (pool->obj->element); g_cond_clear (&pool->empty_cond); /* FIXME have we done enough here ? */ G_OBJECT_CLASS (parent_class)->finalize (object); } static void gst_v4l2_buffer_pool_init (GstV4l2BufferPool * pool) { g_cond_init (&pool->empty_cond); pool->empty = TRUE; pool->orphaned = FALSE; for (gint i = 0; i < VIDEO_MAX_FRAME; i++) g_atomic_int_set (&pool->buffer_state[i], BUFFER_STATE_FREE); } static void gst_v4l2_buffer_pool_class_init (GstV4l2BufferPoolClass * klass) { GObjectClass *object_class = G_OBJECT_CLASS (klass); GstBufferPoolClass *bufferpool_class = GST_BUFFER_POOL_CLASS (klass); object_class->dispose = gst_v4l2_buffer_pool_dispose; object_class->finalize = gst_v4l2_buffer_pool_finalize; bufferpool_class->start = gst_v4l2_buffer_pool_start; bufferpool_class->stop = gst_v4l2_buffer_pool_stop; bufferpool_class->set_config = gst_v4l2_buffer_pool_set_config; bufferpool_class->alloc_buffer = gst_v4l2_buffer_pool_alloc_buffer; bufferpool_class->acquire_buffer = gst_v4l2_buffer_pool_acquire_buffer; bufferpool_class->release_buffer = gst_v4l2_buffer_pool_release_buffer; bufferpool_class->flush_start = gst_v4l2_buffer_pool_flush_start; bufferpool_class->flush_stop = gst_v4l2_buffer_pool_flush_stop; GST_DEBUG_CATEGORY_INIT (v4l2bufferpool_debug, "v4l2bufferpool", 0, "V4L2 Buffer Pool"); GST_DEBUG_CATEGORY_GET (CAT_PERFORMANCE, "GST_PERFORMANCE"); } /** * gst_v4l2_buffer_pool_new: * @obj: the v4l2 object owning the pool * * Construct a new buffer pool. * * Returns: the new pool, use gst_object_unref() to free resources */ GstBufferPool * gst_v4l2_buffer_pool_new (GstV4l2Object * obj, GstCaps * caps) { GstV4l2BufferPool *pool; GstStructure *config; gchar *name, *parent_name; gint fd; fd = obj->dup (obj->video_fd); if (fd < 0) goto dup_failed; /* setting a significant unique name */ parent_name = gst_object_get_name (GST_OBJECT (obj->element)); name = g_strdup_printf ("%s:pool%u:%s", parent_name, obj->pool_seq++, V4L2_TYPE_IS_OUTPUT (obj->type) ? "sink" : "src"); g_free (parent_name); pool = (GstV4l2BufferPool *) g_object_new (GST_TYPE_V4L2_BUFFER_POOL, "name", name, NULL); g_object_ref_sink (pool); g_free (name); pool->video_fd = fd; pool->obj = obj; pool->vallocator = gst_v4l2_allocator_new (GST_OBJECT (pool), obj); if (pool->vallocator == NULL) goto allocator_failed; gst_object_ref (obj->element); config = gst_buffer_pool_get_config (GST_BUFFER_POOL_CAST (pool)); gst_buffer_pool_config_set_params (config, caps, obj->info.size, 0, 0); /* This will simply set a default config, but will not configure the pool * because min and max are not valid */ gst_buffer_pool_set_config (GST_BUFFER_POOL_CAST (pool), config); return GST_BUFFER_POOL (pool); /* ERRORS */ dup_failed: { GST_ERROR ("failed to dup fd %d (%s)", errno, g_strerror (errno)); return NULL; } allocator_failed: { GST_ERROR_OBJECT (pool, "Failed to create V4L2 allocator"); gst_object_unref (pool); return NULL; } } static GstFlowReturn gst_v4l2_do_read (GstV4l2BufferPool * pool, GstBuffer * buf) { GstFlowReturn res; GstV4l2Object *obj = pool->obj; gint amount; GstMapInfo map; gint toread; toread = obj->info.size; GST_LOG_OBJECT (pool, "reading %d bytes into buffer %p", toread, buf); gst_buffer_map (buf, &map, GST_MAP_WRITE); do { if ((res = gst_v4l2_buffer_pool_poll (pool, TRUE)) != GST_FLOW_OK) goto poll_error; amount = obj->read (obj->video_fd, map.data, toread); if (amount == toread) { break; } else if (amount == -1) { if (errno == EAGAIN || errno == EINTR) { continue; } else goto read_error; } else { /* short reads can happen if a signal interrupts the read */ continue; } } while (TRUE); GST_LOG_OBJECT (pool, "read %d bytes", amount); gst_buffer_unmap (buf, &map); gst_buffer_resize (buf, 0, amount); return GST_FLOW_OK; /* ERRORS */ poll_error: { GST_DEBUG ("poll error %s", gst_flow_get_name (res)); goto cleanup; } read_error: { GST_ELEMENT_ERROR (obj->element, RESOURCE, READ, (_("Error reading %d bytes from device '%s'."), toread, obj->videodev), GST_ERROR_SYSTEM); res = GST_FLOW_ERROR; goto cleanup; } cleanup: { gst_buffer_unmap (buf, &map); gst_buffer_resize (buf, 0, 0); return res; } } /** * gst_v4l2_buffer_pool_process: * @bpool: a #GstBufferPool * @buf: a #GstBuffer, maybe be replaced * @frame_number: 32 bit frame number or %NULL * * Process @buf in @bpool. For capture devices, this functions fills @buf with * data from the device. For output devices, this functions send the contents of * @buf to the device for playback. * * If non-%NULL and an output device, @frame_number is stored inside the timestamp for output devices and read * back from the timestamp for capture devices. * * Returns: %GST_FLOW_OK on success. */ GstFlowReturn gst_v4l2_buffer_pool_process (GstV4l2BufferPool * pool, GstBuffer ** buf, guint32 * frame_number) { GstFlowReturn ret = GST_FLOW_OK; GstBufferPool *bpool = GST_BUFFER_POOL_CAST (pool); GstV4l2Object *obj = pool->obj; GST_DEBUG_OBJECT (pool, "process buffer %p", *buf); if (GST_BUFFER_POOL_IS_FLUSHING (pool)) return GST_FLOW_FLUSHING; switch (obj->type) { case V4L2_BUF_TYPE_VIDEO_CAPTURE: case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE: /* capture */ switch (obj->mode) { case GST_V4L2_IO_RW: /* capture into the buffer */ ret = gst_v4l2_do_read (pool, *buf); break; case GST_V4L2_IO_MMAP: case GST_V4L2_IO_DMABUF: { GstBuffer *tmp; if ((*buf)->pool == bpool) { guint num_queued; gsize size = gst_buffer_get_size (*buf); /* Legacy M2M devices return empty buffer when drained */ if (size == 0 && GST_V4L2_IS_M2M (obj->device_caps)) { gst_v4l2_buffer_pool_resize_buffer (bpool, *buf); goto eos; } if (GST_VIDEO_INFO_FORMAT (&pool->caps_info) != GST_VIDEO_FORMAT_ENCODED && size < pool->size) goto buffer_truncated; num_queued = g_atomic_int_get (&pool->num_queued); GST_TRACE_OBJECT (pool, "Only %i buffer left in the capture queue.", num_queued); /* If we have no more buffer, and can allocate it time to do so */ if (num_queued == 0) { if (GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, MMAP)) { GST_DEBUG_OBJECT (pool, "Resurrect for empty queue"); ret = gst_v4l2_buffer_pool_resurrect_buffer (pool); if (ret == GST_FLOW_OK || ret == GST_FLOW_FLUSHING) goto done; } } /* start copying buffers when we are running low on buffers */ if (num_queued < pool->copy_threshold) { GstBuffer *copy; if (GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, MMAP)) { GST_DEBUG_OBJECT (pool, "Resurrect for threshold"); ret = gst_v4l2_buffer_pool_resurrect_buffer (pool); if (ret == GST_FLOW_OK || ret == GST_FLOW_FLUSHING) goto done; } /* copy the buffer */ copy = gst_buffer_copy_region (*buf, GST_BUFFER_COPY_ALL | GST_BUFFER_COPY_DEEP, 0, -1); GST_LOG_OBJECT (pool, "copy buffer %p->%p", *buf, copy); /* and requeue so that we can continue capturing */ gst_buffer_unref (*buf); *buf = copy; } ret = GST_FLOW_OK; /* nothing, data was inside the buffer when we did _acquire() */ goto done; } /* buffer not from our pool, grab a frame and copy it into the target */ if ((ret = gst_v4l2_buffer_pool_dqbuf (pool, &tmp, NULL, TRUE)) != GST_FLOW_OK) goto done; /* An empty buffer on capture indicates the end of stream */ if (gst_buffer_get_size (tmp) == 0) { gst_v4l2_buffer_pool_complete_release_buffer (bpool, tmp, FALSE); /* Legacy M2M devices return empty buffer when drained */ if (GST_V4L2_IS_M2M (obj->device_caps)) { gst_v4l2_buffer_pool_resize_buffer (bpool, *buf); goto eos; } } ret = gst_v4l2_buffer_pool_copy_buffer (pool, *buf, tmp); /* an queue the buffer again after the copy */ gst_v4l2_buffer_pool_complete_release_buffer (bpool, tmp, FALSE); if (ret != GST_FLOW_OK) goto copy_failed; break; } case GST_V4L2_IO_USERPTR: { struct UserPtrData *data; GstBuffer *tmp; /* Replace our buffer with downstream allocated buffer */ data = gst_mini_object_steal_qdata (GST_MINI_OBJECT (*buf), GST_V4L2_IMPORT_QUARK); tmp = gst_buffer_ref (data->buffer); _unmap_userptr_frame (data); /* Now tmp is writable, copy the flags and timestamp */ gst_buffer_copy_into (tmp, *buf, GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS, 0, -1); gst_buffer_replace (buf, tmp); gst_buffer_unref (tmp); break; } case GST_V4L2_IO_DMABUF_IMPORT: { GstBuffer *tmp; /* Replace our buffer with downstream allocated buffer */ tmp = gst_mini_object_steal_qdata (GST_MINI_OBJECT (*buf), GST_V4L2_IMPORT_QUARK); gst_buffer_copy_into (tmp, *buf, GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS, 0, -1); gst_buffer_replace (buf, tmp); gst_buffer_unref (tmp); break; } default: g_assert_not_reached (); break; } break; case V4L2_BUF_TYPE_VIDEO_OUTPUT: case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE: /* playback */ switch (obj->mode) { case GST_V4L2_IO_RW: /* FIXME, do write() */ GST_WARNING_OBJECT (pool, "implement write()"); break; case GST_V4L2_IO_USERPTR: case GST_V4L2_IO_DMABUF_IMPORT: case GST_V4L2_IO_DMABUF: case GST_V4L2_IO_MMAP: { GstBuffer *to_queue = NULL; GstBuffer *buffer; GstV4l2MemoryGroup *group; gint index; gboolean outstanding; gsize queued_size = 0; gsize remaining_size = 0; guint split_count = 1; guint num_queued; if ((*buf)->pool != bpool) goto copying; /* Output buffers don't have to be writable */ if (!gst_v4l2_is_buffer_valid (*buf, &group, FALSE)) goto copying; index = group->buffer.index; GST_LOG_OBJECT (pool, "processing buffer %i from our pool", index); if (g_atomic_int_get (&pool->buffer_state[index]) & BUFFER_STATE_QUEUED) { GST_LOG_OBJECT (pool, "buffer %i already queued, copying", index); goto copying; } /* we can queue directly */ to_queue = gst_buffer_ref (*buf); copying: if (to_queue == NULL) { GstBufferPoolAcquireParams params = { 0 }; GST_LOG_OBJECT (pool, "alloc buffer from our pool"); /* this can return EOS if all buffers are outstanding which would * be strange because we would expect the upstream element to have * allocated them and returned to us.. */ params.flags = GST_BUFFER_POOL_ACQUIRE_FLAG_DONTWAIT; ret = gst_buffer_pool_acquire_buffer (bpool, &to_queue, ¶ms); if (ret != GST_FLOW_OK) goto acquire_failed; ret = gst_v4l2_buffer_pool_prepare_buffer (pool, to_queue, *buf); if (ret != GST_FLOW_OK) { gst_buffer_unref (to_queue); goto prepare_failed; } /* retrieve the group */ gst_v4l2_is_buffer_valid (to_queue, &group, TRUE); } if ((ret = gst_v4l2_buffer_pool_qbuf (pool, to_queue, group, frame_number)) != GST_FLOW_OK) goto queue_failed; /* if we are not streaming yet (this is the first buffer, start * streaming now */ if (!gst_v4l2_buffer_pool_streamon (pool)) { /* don't check return value because qbuf would have failed */ gst_v4l2_is_buffer_valid (to_queue, &group, TRUE); /* qbuf has stored to_queue buffer but we are not in * streaming state, so the flush logic won't be performed. * To avoid leaks, flush the allocator and restore the queued * buffer as non-queued */ gst_v4l2_allocator_flush (pool->vallocator); pool->buffers[group->buffer.index] = NULL; g_atomic_int_and (&pool->buffer_state[group->buffer.index], ~BUFFER_STATE_QUEUED); gst_mini_object_set_qdata (GST_MINI_OBJECT (to_queue), GST_V4L2_IMPORT_QUARK, NULL, NULL); gst_buffer_unref (to_queue); g_atomic_int_add (&pool->num_queued, -1); goto start_failed; } /* Save the amount of data that has been submitted for encoded data */ if (GST_VIDEO_INFO_FORMAT (&pool->caps_info) == GST_VIDEO_FORMAT_ENCODED) { queued_size = gst_buffer_get_size (to_queue); remaining_size = gst_buffer_get_size (*buf) - queued_size; } /* Remove our ref, we will still hold this buffer in acquire as needed, * otherwise the pool will think it is outstanding and will refuse to stop. */ gst_clear_buffer (&to_queue); /* release as many buffer as possible */ while (gst_v4l2_buffer_pool_dqbuf (pool, &buffer, &outstanding, FALSE) == GST_FLOW_OK) { if (!outstanding) gst_v4l2_buffer_pool_complete_release_buffer (bpool, buffer, FALSE); } num_queued = g_atomic_int_get (&pool->num_queued); if (num_queued >= pool->min_latency && num_queued > split_count) { /* all buffers are queued, try to dequeue one and release it back * into the pool so that _acquire can get to it again. */ ret = gst_v4l2_buffer_pool_dqbuf (pool, &buffer, &outstanding, TRUE); if (ret == GST_FLOW_OK && !outstanding) /* release the rendered buffer back into the pool. This wakes up any * thread waiting for a buffer in _acquire(). */ gst_v4l2_buffer_pool_complete_release_buffer (bpool, buffer, FALSE); } /* For encoded data, just queue de remaining in the next available * buffer. */ if (remaining_size) { *buf = gst_buffer_make_writable (*buf); gst_buffer_resize (*buf, queued_size, -1); split_count++; goto copying; } break; } default: g_assert_not_reached (); break; } break; default: g_assert_not_reached (); break; } done: return ret; /* ERRORS */ copy_failed: { GST_ERROR_OBJECT (pool, "failed to copy buffer"); return ret; } buffer_truncated: { GST_WARNING_OBJECT (pool, "Dropping truncated buffer, this is likely a driver bug."); gst_buffer_unref (*buf); *buf = NULL; return GST_V4L2_FLOW_CORRUPTED_BUFFER; } eos: { GST_DEBUG_OBJECT (pool, "end of sequence reached"); gst_buffer_unref (*buf); *buf = NULL; return GST_V4L2_FLOW_LAST_BUFFER; } acquire_failed: { if (ret == GST_FLOW_FLUSHING) GST_DEBUG_OBJECT (pool, "flushing"); else GST_WARNING_OBJECT (pool, "failed to acquire a buffer: %s", gst_flow_get_name (ret)); return ret; } prepare_failed: { GST_ERROR_OBJECT (pool, "failed to prepare data"); return ret; } queue_failed: { GST_ERROR_OBJECT (pool, "failed to queue buffer"); return ret; } start_failed: { GST_ERROR_OBJECT (pool, "failed to start streaming"); return GST_FLOW_ERROR; } } void gst_v4l2_buffer_pool_set_other_pool (GstV4l2BufferPool * pool, GstBufferPool * other_pool) { g_return_if_fail (!gst_buffer_pool_is_active (GST_BUFFER_POOL (pool))); if (pool->other_pool) gst_object_unref (pool->other_pool); pool->other_pool = gst_object_ref (other_pool); } void gst_v4l2_buffer_pool_copy_at_threshold (GstV4l2BufferPool * pool, gboolean copy) { GST_OBJECT_LOCK (pool); pool->enable_copy_threshold = copy; GST_OBJECT_UNLOCK (pool); } static GstFlowReturn gst_v4l2_buffer_pool_flush_events (GstV4l2Object * v4l2object) { GstFlowReturn ret = GST_FLOW_OK; gboolean event_found; /* FIXME simplify this when we drop legacy support for driver without poll() * support. When we do, we can switch the video_fd to non blocking, and just * pop the events directly. */ do { struct v4l2_event event = { 0, }; gint poll_ret; event_found = FALSE; gst_poll_set_flushing (v4l2object->poll, FALSE); do { /* GstPoll don't have 0ns timeout, but 1 will do */ poll_ret = gst_poll_wait (v4l2object->poll, 1); } while (poll_ret == EAGAIN || poll_ret == EINTR); if (gst_poll_fd_has_pri (v4l2object->poll, &v4l2object->pollfd)) { if (!gst_v4l2_dequeue_event (v4l2object, &event)) return GST_FLOW_ERROR; event_found = TRUE; if (event.type == V4L2_EVENT_SOURCE_CHANGE && (event.u.src_change.changes & V4L2_EVENT_SRC_CH_RESOLUTION)) { GST_DEBUG_OBJECT (v4l2object->dbg_obj, "Can't streamon capture as the resolution have changed."); ret = GST_V4L2_FLOW_RESOLUTION_CHANGE; } } } while (event_found); return ret; } GstFlowReturn gst_v4l2_buffer_pool_flush (GstV4l2Object * v4l2object) { GstBufferPool *bpool = gst_v4l2_object_get_buffer_pool (v4l2object); GstV4l2BufferPool *pool; GstFlowReturn ret = GST_FLOW_OK; if (!bpool) return GST_FLOW_ERROR; pool = GST_V4L2_BUFFER_POOL (bpool); GST_OBJECT_LOCK (pool); gst_v4l2_buffer_pool_streamoff (pool); GST_OBJECT_UNLOCK (pool); if (!V4L2_TYPE_IS_OUTPUT (pool->obj->type)) { ret = gst_v4l2_buffer_pool_flush_events (v4l2object); /* If the format haven't change, avoid reallocation to go back to * streaming */ if (ret == GST_FLOW_OK) ret = gst_v4l2_buffer_pool_streamon (pool); } gst_object_unref (bpool); return ret; } /** * gst_v4l2_buffer_pool_enable_resolution_change: * @pool: a #GstBufferPool * * When this is called, the pool will subscribe to the * %V4L2_EVENT_SOURCE_CHANGE. Upon receiving this event, it will notify * the element acquiring buffer with the special flow return * %GST_V4L2_FLOW_RESOLUTION_CHANGE. */ void gst_v4l2_buffer_pool_enable_resolution_change (GstV4l2BufferPool * pool) { gst_v4l2_object_subscribe_event (pool->obj, V4L2_EVENT_SOURCE_CHANGE); }