gstreamer/ext/libpng/gstpngdec.c
2012-01-25 12:41:42 +01:00

976 lines
26 KiB
C

/* GStreamer
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
*
* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
*/
/**
* SECTION:element-pngdec
*
* Decodes png images. If there is no framerate set on sink caps, it sends EOS
* after the first picture.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstpngdec.h"
#include <stdlib.h>
#include <string.h>
#include <gst/video/video.h>
#include <gst/gst-i18n-plugin.h>
GST_DEBUG_CATEGORY_STATIC (pngdec_debug);
#define GST_CAT_DEFAULT pngdec_debug
static gboolean gst_pngdec_libpng_init (GstPngDec * pngdec);
static gboolean gst_pngdec_libpng_clear (GstPngDec * pngdec);
static GstStateChangeReturn gst_pngdec_change_state (GstElement * element,
GstStateChange transition);
static gboolean gst_pngdec_sink_activate_mode (GstPad * sinkpad,
GstObject * parent, GstPadMode mode, gboolean active);
static gboolean gst_pngdec_sink_activate (GstPad * sinkpad, GstObject * parent);
static GstFlowReturn gst_pngdec_caps_create_and_set (GstPngDec * pngdec);
static void gst_pngdec_task (GstPad * pad);
static GstFlowReturn gst_pngdec_chain (GstPad * pad, GstObject * parent,
GstBuffer * buffer);
static gboolean gst_pngdec_sink_event (GstPad * pad, GstObject * parent,
GstEvent * event);
static gboolean gst_pngdec_sink_setcaps (GstPngDec * pngdec, GstCaps * caps);
static GstFlowReturn gst_pngdec_negotiate_pool (GstPngDec * dec,
GstCaps * caps, GstVideoInfo * info);
static GstStaticPadTemplate gst_pngdec_src_pad_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("{ RGBA, RGB }"))
);
static GstStaticPadTemplate gst_pngdec_sink_pad_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("image/png")
);
#define gst_pngdec_parent_class parent_class
G_DEFINE_TYPE (GstPngDec, gst_pngdec, GST_TYPE_ELEMENT);
static void
gst_pngdec_class_init (GstPngDecClass * klass)
{
GstElementClass *gstelement_class;
gstelement_class = (GstElementClass *) klass;
gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_pngdec_change_state);
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&gst_pngdec_src_pad_template));
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&gst_pngdec_sink_pad_template));
gst_element_class_set_details_simple (gstelement_class, "PNG image decoder",
"Codec/Decoder/Image",
"Decode a png video frame to a raw image",
"Wim Taymans <wim@fluendo.com>");
GST_DEBUG_CATEGORY_INIT (pngdec_debug, "pngdec", 0, "PNG image decoder");
}
static void
gst_pngdec_init (GstPngDec * pngdec)
{
pngdec->sinkpad =
gst_pad_new_from_static_template (&gst_pngdec_sink_pad_template, "sink");
gst_pad_set_activate_function (pngdec->sinkpad,
GST_DEBUG_FUNCPTR (gst_pngdec_sink_activate));
gst_pad_set_activatemode_function (pngdec->sinkpad,
GST_DEBUG_FUNCPTR (gst_pngdec_sink_activate_mode));
gst_pad_set_chain_function (pngdec->sinkpad,
GST_DEBUG_FUNCPTR (gst_pngdec_chain));
gst_pad_set_event_function (pngdec->sinkpad,
GST_DEBUG_FUNCPTR (gst_pngdec_sink_event));
gst_element_add_pad (GST_ELEMENT (pngdec), pngdec->sinkpad);
pngdec->srcpad =
gst_pad_new_from_static_template (&gst_pngdec_src_pad_template, "src");
gst_pad_use_fixed_caps (pngdec->srcpad);
gst_element_add_pad (GST_ELEMENT (pngdec), pngdec->srcpad);
pngdec->buffer_out = NULL;
pngdec->png = NULL;
pngdec->info = NULL;
pngdec->endinfo = NULL;
pngdec->setup = FALSE;
pngdec->color_type = -1;
pngdec->width = -1;
pngdec->height = -1;
pngdec->fps_n = 0;
pngdec->fps_d = 1;
pngdec->in_timestamp = GST_CLOCK_TIME_NONE;
pngdec->in_duration = GST_CLOCK_TIME_NONE;
gst_segment_init (&pngdec->segment, GST_FORMAT_UNDEFINED);
pngdec->image_ready = FALSE;
}
static void
user_error_fn (png_structp png_ptr, png_const_charp error_msg)
{
GST_ERROR ("%s", error_msg);
}
static void
user_warning_fn (png_structp png_ptr, png_const_charp warning_msg)
{
GST_WARNING ("%s", warning_msg);
}
static void
user_info_callback (png_structp png_ptr, png_infop info)
{
GstPngDec *pngdec = NULL;
GstFlowReturn ret = GST_FLOW_OK;
GstBuffer *buffer = NULL;
pngdec = GST_PNGDEC (png_get_io_ptr (png_ptr));
GST_LOG ("info ready");
/* Generate the caps and configure */
ret = gst_pngdec_caps_create_and_set (pngdec);
if (ret != GST_FLOW_OK) {
goto beach;
}
if (gst_pad_check_reconfigure (pngdec->srcpad)) {
GstCaps *caps;
caps = gst_pad_get_current_caps (pngdec->srcpad);
gst_pngdec_negotiate_pool (pngdec, caps, &pngdec->vinfo);
gst_caps_unref (caps);
}
/* Allocate output buffer */
g_assert (pngdec->pool);
ret = gst_buffer_pool_acquire_buffer (pngdec->pool, &buffer, NULL);
if (ret != GST_FLOW_OK) {
GST_DEBUG_OBJECT (pngdec, "failed to acquire buffer");
ret = GST_FLOW_ERROR;
goto beach;
}
pngdec->buffer_out = buffer;
beach:
pngdec->ret = ret;
}
static void
user_endrow_callback (png_structp png_ptr, png_bytep new_row,
png_uint_32 row_num, int pass)
{
GstPngDec *pngdec = NULL;
pngdec = GST_PNGDEC (png_get_io_ptr (png_ptr));
/* FIXME: implement interlaced pictures */
/* If buffer_out doesn't exist, it means buffer_alloc failed, which
* will already have set the return code */
if (GST_IS_BUFFER (pngdec->buffer_out)) {
GstVideoFrame frame;
GstBuffer *buffer = pngdec->buffer_out;
size_t offset;
gint width;
guint8 *data;
if (!gst_video_frame_map (&frame, &pngdec->vinfo, buffer, GST_MAP_WRITE)) {
pngdec->ret = GST_FLOW_ERROR;
return;
}
data = GST_VIDEO_FRAME_COMP_DATA (&frame, 0);
offset = row_num * GST_VIDEO_FRAME_COMP_STRIDE (&frame, 0);
GST_LOG ("got row %u, copying in buffer %p at offset %" G_GSIZE_FORMAT,
(guint) row_num, pngdec->buffer_out, offset);
width = GST_ROUND_UP_4 (png_get_rowbytes (pngdec->png, pngdec->info));
memcpy (data + offset, new_row, width);
gst_video_frame_unmap (&frame);
pngdec->ret = GST_FLOW_OK;
}
}
static gboolean
buffer_clip (GstPngDec * dec, GstBuffer * buffer)
{
gboolean res = TRUE;
guint64 cstart, cstop;
if ((!GST_CLOCK_TIME_IS_VALID (GST_BUFFER_TIMESTAMP (buffer))) ||
(!GST_CLOCK_TIME_IS_VALID (GST_BUFFER_DURATION (buffer))) ||
(dec->segment.format != GST_FORMAT_TIME))
goto beach;
cstart = GST_BUFFER_TIMESTAMP (buffer);
cstop = GST_BUFFER_DURATION (buffer);
if ((res = gst_segment_clip (&dec->segment, GST_FORMAT_TIME,
cstart, cstart + cstop, &cstart, &cstop))) {
GST_BUFFER_TIMESTAMP (buffer) = cstart;
GST_BUFFER_DURATION (buffer) = cstop - cstart;
}
beach:
return res;
}
static void
user_end_callback (png_structp png_ptr, png_infop info)
{
GstPngDec *pngdec = NULL;
pngdec = GST_PNGDEC (png_get_io_ptr (png_ptr));
GST_LOG_OBJECT (pngdec, "and we are done reading this image");
if (!pngdec->buffer_out)
return;
if (GST_CLOCK_TIME_IS_VALID (pngdec->in_timestamp))
GST_BUFFER_TIMESTAMP (pngdec->buffer_out) = pngdec->in_timestamp;
if (GST_CLOCK_TIME_IS_VALID (pngdec->in_duration))
GST_BUFFER_DURATION (pngdec->buffer_out) = pngdec->in_duration;
/* buffer clipping */
if (buffer_clip (pngdec, pngdec->buffer_out)) {
/* Push our buffer and then EOS if needed */
GST_LOG_OBJECT (pngdec, "pushing buffer with ts=%" GST_TIME_FORMAT,
GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (pngdec->buffer_out)));
pngdec->ret = gst_pad_push (pngdec->srcpad, pngdec->buffer_out);
} else {
GST_LOG_OBJECT (pngdec, "dropped decoded buffer");
gst_buffer_unref (pngdec->buffer_out);
}
pngdec->buffer_out = NULL;
pngdec->image_ready = TRUE;
}
static void
user_read_data (png_structp png_ptr, png_bytep data, png_size_t length)
{
GstPngDec *pngdec;
GstBuffer *buffer;
GstFlowReturn ret = GST_FLOW_OK;
guint size;
pngdec = GST_PNGDEC (png_get_io_ptr (png_ptr));
GST_LOG ("reading %" G_GSIZE_FORMAT " bytes of data at offset %d", length,
pngdec->offset);
ret = gst_pad_pull_range (pngdec->sinkpad, pngdec->offset, length, &buffer);
if (ret != GST_FLOW_OK)
goto pause;
size = gst_buffer_get_size (buffer);
if (size != length)
goto short_buffer;
gst_buffer_extract (buffer, 0, data, size);
gst_buffer_unref (buffer);
pngdec->offset += length;
return;
/* ERRORS */
pause:
{
GST_INFO_OBJECT (pngdec, "pausing task, reason %s",
gst_flow_get_name (ret));
gst_pad_pause_task (pngdec->sinkpad);
if (ret == GST_FLOW_EOS) {
gst_pad_push_event (pngdec->srcpad, gst_event_new_eos ());
} else if (ret < GST_FLOW_EOS || ret == GST_FLOW_NOT_LINKED) {
GST_ELEMENT_ERROR (pngdec, STREAM, FAILED,
(_("Internal data stream error.")),
("stream stopped, reason %s", gst_flow_get_name (ret)));
gst_pad_push_event (pngdec->srcpad, gst_event_new_eos ());
}
png_error (png_ptr, "Internal data stream error.");
return;
}
short_buffer:
{
gst_buffer_unref (buffer);
GST_ELEMENT_ERROR (pngdec, STREAM, FAILED,
(_("Internal data stream error.")),
("Read %u, needed %" G_GSIZE_FORMAT "bytes", size, length));
ret = GST_FLOW_ERROR;
goto pause;
}
}
static GstFlowReturn
gst_pngdec_negotiate_pool (GstPngDec * dec, GstCaps * caps, GstVideoInfo * info)
{
GstQuery *query;
GstBufferPool *pool = NULL;
guint size, min, max, prefix, alignment;
GstStructure *config;
/* find a pool for the negotiated caps now */
query = gst_query_new_allocation (caps, TRUE);
if (gst_pad_peer_query (dec->srcpad, query)) {
GST_DEBUG_OBJECT (dec, "got downstream ALLOCATION hints");
/* we got configuration from our peer, parse them */
gst_query_parse_allocation_params (query, &size, &min, &max, &prefix,
&alignment, &pool);
size = MAX (size, info->size);
} else {
GST_DEBUG_OBJECT (dec, "didn't get downstream ALLOCATION hints");
size = info->size;
min = max = 0;
prefix = 0;
alignment = 0;
}
if (pool == NULL) {
/* we did not get a pool, make one ourselves then */
pool = gst_buffer_pool_new ();
}
if (dec->pool)
gst_object_unref (dec->pool);
dec->pool = pool;
config = gst_buffer_pool_get_config (pool);
gst_buffer_pool_config_set (config, caps, size, min, max, prefix, alignment);
/* just set the option, if the pool can support it we will transparently use
* it through the video info API. We could also see if the pool support this
* option and only activate it then. */
gst_buffer_pool_config_add_option (config, GST_BUFFER_POOL_OPTION_VIDEO_META);
gst_buffer_pool_set_config (pool, config);
/* and activate */
gst_buffer_pool_set_active (pool, TRUE);
gst_query_unref (query);
return GST_FLOW_OK;
}
static GstFlowReturn
gst_pngdec_caps_create_and_set (GstPngDec * pngdec)
{
GstFlowReturn ret = GST_FLOW_OK;
GstCaps *caps = NULL, *res = NULL;
GstPadTemplate *templ = NULL;
gint bpc = 0, color_type;
png_uint_32 width, height;
GstVideoFormat format;
GstVideoInfo vinfo = { 0, };
g_return_val_if_fail (GST_IS_PNGDEC (pngdec), GST_FLOW_ERROR);
/* Get bits per channel */
bpc = png_get_bit_depth (pngdec->png, pngdec->info);
if (bpc > 8) {
/* Add alpha channel if 16-bit depth */
png_set_add_alpha (pngdec->png, 0xffff, PNG_FILLER_BEFORE);
png_set_swap (pngdec->png);
}
/* Get Color type */
color_type = png_get_color_type (pngdec->png, pngdec->info);
#if 0
/* We used to have this HACK to reverse the outgoing bytes, but the problem
* that originally required the hack seems to have been in ffmpegcolorspace's
* RGBA descriptions. It doesn't seem needed now that's fixed, but might
* still be needed on big-endian systems, I'm not sure. J.S. 6/7/2007 */
if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
png_set_bgr (pngdec->png);
#endif
/* Gray scale converted to RGB and upscaled to 8 bits */
if ((color_type == PNG_COLOR_TYPE_GRAY_ALPHA) ||
(color_type == PNG_COLOR_TYPE_GRAY)) {
GST_LOG_OBJECT (pngdec, "converting grayscale png to RGB");
png_set_gray_to_rgb (pngdec->png);
if (bpc < 8) { /* Convert to 8 bits */
GST_LOG_OBJECT (pngdec, "converting grayscale image to 8 bits");
#if PNG_LIBPNG_VER < 10400
png_set_gray_1_2_4_to_8 (pngdec->png);
#else
png_set_expand_gray_1_2_4_to_8 (pngdec->png);
#endif
}
}
/* Palette converted to RGB */
if (color_type == PNG_COLOR_TYPE_PALETTE) {
GST_LOG_OBJECT (pngdec, "converting palette png to RGB");
png_set_palette_to_rgb (pngdec->png);
}
/* Update the info structure */
png_read_update_info (pngdec->png, pngdec->info);
/* Get IHDR header again after transformation settings */
png_get_IHDR (pngdec->png, pngdec->info, &width, &height,
&bpc, &pngdec->color_type, NULL, NULL, NULL);
pngdec->width = width;
pngdec->height = height;
GST_LOG_OBJECT (pngdec, "this is a %dx%d PNG image", pngdec->width,
pngdec->height);
switch (pngdec->color_type) {
case PNG_COLOR_TYPE_RGB:
GST_LOG_OBJECT (pngdec, "we have no alpha channel, depth is 24 bits");
format = GST_VIDEO_FORMAT_RGB;
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
GST_LOG_OBJECT (pngdec, "we have an alpha channel, depth is 32 bits");
format = GST_VIDEO_FORMAT_RGBA;
break;
default:
GST_ELEMENT_ERROR (pngdec, STREAM, NOT_IMPLEMENTED, (NULL),
("pngdec does not support this color type"));
ret = GST_FLOW_NOT_SUPPORTED;
goto beach;
}
gst_video_info_set_format (&vinfo, format, pngdec->width, pngdec->height);
vinfo.fps_n = pngdec->fps_n;
vinfo.fps_d = pngdec->fps_d;
vinfo.par_n = 1;
vinfo.par_d = 1;
if (memcmp (&vinfo, &pngdec->vinfo, sizeof (vinfo)) == 0) {
GST_DEBUG_OBJECT (pngdec, "video info unchanged, skip negotiation");
ret = GST_FLOW_OK;
goto beach;
}
pngdec->vinfo = vinfo;
caps = gst_video_info_to_caps (&pngdec->vinfo);
templ = gst_static_pad_template_get (&gst_pngdec_src_pad_template);
res = gst_caps_intersect (caps, gst_pad_template_get_caps (templ));
gst_caps_unref (caps);
gst_object_unref (templ);
if (!gst_pad_set_caps (pngdec->srcpad, res))
ret = GST_FLOW_NOT_NEGOTIATED;
/* clear pending reconfigure */
gst_pad_check_reconfigure (pngdec->srcpad);
GST_DEBUG_OBJECT (pngdec, "our caps %" GST_PTR_FORMAT, res);
gst_pngdec_negotiate_pool (pngdec, res, &pngdec->vinfo);
gst_caps_unref (res);
/* Push a newsegment event */
if (pngdec->need_newsegment) {
gst_segment_init (&pngdec->segment, GST_FORMAT_TIME);
gst_pad_push_event (pngdec->srcpad,
gst_event_new_segment (&pngdec->segment));
pngdec->need_newsegment = FALSE;
}
beach:
return ret;
}
static void
gst_pngdec_task (GstPad * pad)
{
GstPngDec *pngdec;
GstBuffer *buffer = NULL;
gint i = 0;
png_bytep *rows, inp = NULL;
GstFlowReturn ret = GST_FLOW_OK;
GstVideoFrame frame;
pngdec = GST_PNGDEC (GST_OBJECT_PARENT (pad));
GST_LOG_OBJECT (pngdec, "read frame");
/* Let libpng come back here on error */
if (setjmp (png_jmpbuf (pngdec->png))) {
ret = GST_FLOW_ERROR;
goto pause;
}
/* Set reading callback */
png_set_read_fn (pngdec->png, pngdec, user_read_data);
/* Read info */
png_read_info (pngdec->png, pngdec->info);
pngdec->fps_n = 0;
pngdec->fps_d = 1;
/* Generate the caps and configure */
ret = gst_pngdec_caps_create_and_set (pngdec);
if (ret != GST_FLOW_OK) {
goto pause;
}
/* Allocate output buffer */
g_assert (pngdec->pool);
ret = gst_buffer_pool_acquire_buffer (pngdec->pool, &buffer, NULL);
if (ret != GST_FLOW_OK)
goto pause;
rows = (png_bytep *) g_malloc (sizeof (png_bytep) * pngdec->height);
if (!gst_video_frame_map (&frame, &pngdec->vinfo, buffer, GST_MAP_WRITE))
goto invalid_frame;
inp = GST_VIDEO_FRAME_COMP_DATA (&frame, 0);
for (i = 0; i < pngdec->height; i++) {
rows[i] = inp;
inp += GST_VIDEO_FRAME_COMP_STRIDE (&frame, 0);
}
/* Read the actual picture */
png_read_image (pngdec->png, rows);
g_free (rows);
gst_video_frame_unmap (&frame);
inp = NULL;
/* Push the raw RGB frame */
ret = gst_pad_push (pngdec->srcpad, buffer);
buffer = NULL;
if (ret != GST_FLOW_OK)
goto pause;
/* And we are done */
gst_pad_pause_task (pngdec->sinkpad);
gst_pad_push_event (pngdec->srcpad, gst_event_new_eos ());
return;
pause:
{
if (inp)
gst_video_frame_unmap (&frame);
if (buffer)
gst_buffer_unref (buffer);
GST_INFO_OBJECT (pngdec, "pausing task, reason %s",
gst_flow_get_name (ret));
gst_pad_pause_task (pngdec->sinkpad);
if (ret == GST_FLOW_EOS) {
gst_pad_push_event (pngdec->srcpad, gst_event_new_eos ());
} else if (ret == GST_FLOW_NOT_LINKED || ret < GST_FLOW_EOS) {
GST_ELEMENT_ERROR (pngdec, STREAM, FAILED,
(_("Internal data stream error.")),
("stream stopped, reason %s", gst_flow_get_name (ret)));
gst_pad_push_event (pngdec->srcpad, gst_event_new_eos ());
}
}
invalid_frame:
{
GST_DEBUG_OBJECT (pngdec, "could not map video frame");
ret = GST_FLOW_ERROR;
goto pause;
}
}
static GstFlowReturn
gst_pngdec_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer)
{
GstPngDec *pngdec;
GstFlowReturn ret = GST_FLOW_OK;
GstMapInfo map = GST_MAP_INFO_INIT;
pngdec = GST_PNGDEC (parent);
if (G_UNLIKELY (!pngdec->setup))
goto not_configured;
/* Something is going wrong in our callbacks */
ret = pngdec->ret;
if (G_UNLIKELY (ret != GST_FLOW_OK)) {
GST_WARNING_OBJECT (pngdec, "we have a pending return code of %d", ret);
goto beach;
}
/* Let libpng come back here on error */
if (setjmp (png_jmpbuf (pngdec->png))) {
GST_WARNING_OBJECT (pngdec, "error during decoding");
ret = GST_FLOW_ERROR;
goto beach;
}
pngdec->in_timestamp = GST_BUFFER_TIMESTAMP (buffer);
pngdec->in_duration = GST_BUFFER_DURATION (buffer);
gst_buffer_map (buffer, &map, GST_MAP_READ);
GST_LOG_OBJECT (pngdec, "Got buffer, size=%d", (gint) map.size);
/* Progressive loading of the PNG image */
png_process_data (pngdec->png, pngdec->info, map.data, map.size);
if (pngdec->image_ready) {
if (pngdec->framed) {
/* Reset ourselves for the next frame */
gst_pngdec_libpng_clear (pngdec);
gst_pngdec_libpng_init (pngdec);
GST_LOG_OBJECT (pngdec, "setting up callbacks for next frame");
png_set_progressive_read_fn (pngdec->png, pngdec,
user_info_callback, user_endrow_callback, user_end_callback);
} else {
GST_LOG_OBJECT (pngdec, "sending EOS");
pngdec->ret = gst_pad_push_event (pngdec->srcpad, gst_event_new_eos ());
}
pngdec->image_ready = FALSE;
}
/* grab new return code */
ret = pngdec->ret;
beach:
if (G_LIKELY (map.data))
gst_buffer_unmap (buffer, &map);
/* And release the buffer */
gst_buffer_unref (buffer);
return ret;
/* ERRORS */
not_configured:
{
GST_LOG_OBJECT (pngdec, "we are not configured yet");
ret = GST_FLOW_WRONG_STATE;
goto beach;
}
}
static gboolean
gst_pngdec_sink_setcaps (GstPngDec * pngdec, GstCaps * caps)
{
GstStructure *s;
gint num, denom;
s = gst_caps_get_structure (caps, 0);
if (gst_structure_get_fraction (s, "framerate", &num, &denom)) {
GST_DEBUG_OBJECT (pngdec, "framed input");
pngdec->framed = TRUE;
pngdec->fps_n = num;
pngdec->fps_d = denom;
} else {
GST_DEBUG_OBJECT (pngdec, "single picture input");
pngdec->framed = FALSE;
pngdec->fps_n = 0;
pngdec->fps_d = 1;
}
return TRUE;
}
static gboolean
gst_pngdec_sink_event (GstPad * pad, GstObject * parent, GstEvent * event)
{
GstPngDec *pngdec;
gboolean res;
pngdec = GST_PNGDEC (parent);
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_SEGMENT:{
gst_event_copy_segment (event, &pngdec->segment);
GST_LOG_OBJECT (pngdec, "SEGMENT %" GST_SEGMENT_FORMAT, &pngdec->segment);
if (pngdec->segment.format == GST_FORMAT_TIME) {
pngdec->need_newsegment = FALSE;
res = gst_pad_push_event (pngdec->srcpad, event);
} else {
gst_event_unref (event);
res = TRUE;
}
break;
}
case GST_EVENT_FLUSH_STOP:
{
gst_pngdec_libpng_clear (pngdec);
gst_pngdec_libpng_init (pngdec);
png_set_progressive_read_fn (pngdec->png, pngdec,
user_info_callback, user_endrow_callback, user_end_callback);
pngdec->ret = GST_FLOW_OK;
gst_segment_init (&pngdec->segment, GST_FORMAT_UNDEFINED);
res = gst_pad_push_event (pngdec->srcpad, event);
break;
}
case GST_EVENT_EOS:
{
GST_LOG_OBJECT (pngdec, "EOS");
gst_pngdec_libpng_clear (pngdec);
pngdec->ret = GST_FLOW_EOS;
res = gst_pad_push_event (pngdec->srcpad, event);
break;
}
case GST_EVENT_CAPS:
{
GstCaps *caps;
gst_event_parse_caps (event, &caps);
res = gst_pngdec_sink_setcaps (pngdec, caps);
gst_event_unref (event);
break;
}
default:
res = gst_pad_push_event (pngdec->srcpad, event);
break;
}
return res;
}
/* Clean up the libpng structures */
static gboolean
gst_pngdec_libpng_clear (GstPngDec * pngdec)
{
png_infopp info = NULL, endinfo = NULL;
g_return_val_if_fail (GST_IS_PNGDEC (pngdec), FALSE);
GST_LOG ("cleaning up libpng structures");
if (pngdec->info) {
info = &pngdec->info;
}
if (pngdec->endinfo) {
endinfo = &pngdec->endinfo;
}
if (pngdec->png) {
png_destroy_read_struct (&(pngdec->png), info, endinfo);
pngdec->png = NULL;
pngdec->info = NULL;
pngdec->endinfo = NULL;
}
pngdec->color_type = pngdec->height = pngdec->width = -1;
pngdec->offset = 0;
pngdec->buffer_out = NULL;
pngdec->setup = FALSE;
pngdec->in_timestamp = GST_CLOCK_TIME_NONE;
pngdec->in_duration = GST_CLOCK_TIME_NONE;
return TRUE;
}
static gboolean
gst_pngdec_libpng_init (GstPngDec * pngdec)
{
g_return_val_if_fail (GST_IS_PNGDEC (pngdec), FALSE);
if (pngdec->setup)
return TRUE;
GST_LOG ("init libpng structures");
/* initialize png struct stuff */
pngdec->png = png_create_read_struct (PNG_LIBPNG_VER_STRING,
(png_voidp) NULL, user_error_fn, user_warning_fn);
if (pngdec->png == NULL)
goto init_failed;
pngdec->info = png_create_info_struct (pngdec->png);
if (pngdec->info == NULL)
goto info_failed;
pngdec->endinfo = png_create_info_struct (pngdec->png);
if (pngdec->endinfo == NULL)
goto endinfo_failed;
pngdec->setup = TRUE;
return TRUE;
/* ERRORS */
init_failed:
{
GST_ELEMENT_ERROR (pngdec, LIBRARY, INIT, (NULL),
("Failed to initialize png structure"));
return FALSE;
}
info_failed:
{
gst_pngdec_libpng_clear (pngdec);
GST_ELEMENT_ERROR (pngdec, LIBRARY, INIT, (NULL),
("Failed to initialize info structure"));
return FALSE;
}
endinfo_failed:
{
gst_pngdec_libpng_clear (pngdec);
GST_ELEMENT_ERROR (pngdec, LIBRARY, INIT, (NULL),
("Failed to initialize endinfo structure"));
return FALSE;
}
}
static GstStateChangeReturn
gst_pngdec_change_state (GstElement * element, GstStateChange transition)
{
GstStateChangeReturn ret;
GstPngDec *pngdec;
pngdec = GST_PNGDEC (element);
switch (transition) {
case GST_STATE_CHANGE_READY_TO_PAUSED:
gst_pngdec_libpng_init (pngdec);
pngdec->need_newsegment = TRUE;
pngdec->framed = FALSE;
pngdec->ret = GST_FLOW_OK;
gst_segment_init (&pngdec->segment, GST_FORMAT_UNDEFINED);
break;
default:
break;
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
if (ret != GST_STATE_CHANGE_SUCCESS)
return ret;
switch (transition) {
case GST_STATE_CHANGE_PAUSED_TO_READY:
gst_pngdec_libpng_clear (pngdec);
if (pngdec->pool)
gst_object_unref (pngdec->pool);
break;
default:
break;
}
return ret;
}
/* this function gets called when we activate ourselves in pull mode.
* We can perform random access to the resource and we start a task
* to start reading */
static gboolean
gst_pngdec_sink_activate_mode (GstPad * sinkpad, GstObject * parent,
GstPadMode mode, gboolean active)
{
GstPngDec *pngdec = GST_PNGDEC (parent);
gboolean res;
switch (mode) {
case GST_PAD_MODE_PULL:
if (active) {
res = gst_pad_start_task (sinkpad, (GstTaskFunction) gst_pngdec_task,
sinkpad);
} else {
res = gst_pad_stop_task (sinkpad);
}
break;
case GST_PAD_MODE_PUSH:
GST_DEBUG_OBJECT (pngdec, "activating push/chain function");
if (active) {
pngdec->ret = GST_FLOW_OK;
/* Let libpng come back here on error */
if (setjmp (png_jmpbuf (pngdec->png)))
goto setup_failed;
GST_LOG_OBJECT (pngdec, "setting up progressive loading callbacks");
png_set_progressive_read_fn (pngdec->png, pngdec,
user_info_callback, user_endrow_callback, user_end_callback);
} else {
GST_DEBUG_OBJECT (pngdec, "deactivating push/chain function");
}
res = TRUE;
break;
default:
res = FALSE;
break;
}
return res;
setup_failed:
{
GST_LOG_OBJECT (pngdec, "failed setting up libpng jmpbuf");
gst_pngdec_libpng_clear (pngdec);
return FALSE;
}
}
/* this function is called when the pad is activated and should start
* processing data.
*
* We check if we can do random access to decide if we work push or
* pull based.
*/
static gboolean
gst_pngdec_sink_activate (GstPad * sinkpad, GstObject * parent)
{
GstQuery *query;
gboolean pull_mode;
query = gst_query_new_scheduling ();
if (!gst_pad_peer_query (sinkpad, query)) {
gst_query_unref (query);
goto activate_push;
}
pull_mode = gst_query_has_scheduling_mode (query, GST_PAD_MODE_PULL);
gst_query_unref (query);
if (!pull_mode)
goto activate_push;
GST_DEBUG_OBJECT (sinkpad, "activating pull");
return gst_pad_activate_mode (sinkpad, GST_PAD_MODE_PULL, TRUE);
activate_push:
{
GST_DEBUG_OBJECT (sinkpad, "activating push");
return gst_pad_activate_mode (sinkpad, GST_PAD_MODE_PUSH, TRUE);
}
}