gstreamer/gst/dvbsubenc/gstdvbsubenc.c
2021-04-11 16:16:55 +00:00

605 lines
18 KiB
C

/* GStreamer
* Copyright (C) <2020> Jan Schmidt <jan@centricular.com>
*
* 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 "config.h"
#endif
#include "gstdvbsubenc.h"
#include <string.h>
/**
* SECTION:element-dvbsubenc
* @title: dvbsubenc
* @see_also: dvbsuboverlay
*
* This element encodes AYUV video frames to DVB subpictures.
*
* ## Example pipelines
* |[
* gst-launch-1.0 videotestsrc num-buffers=900 ! video/x-raw,width=720,height=576,framerate=30/1 ! x264enc bitrate=500 ! h264parse ! mpegtsmux name=mux ! filesink location=test.ts filesrc location=test-subtitles.srt ! subparse ! textrender ! dvbsubenc ! mux.
* ]|
* Encode a test video signal and an SRT subtitle file to MPEG-TS with a DVB subpicture track
*
*/
#define DEFAULT_MAX_COLOURS 16
#define DEFAULT_TS_OFFSET 0
enum
{
PROP_0,
PROP_MAX_COLOURS,
PROP_TS_OFFSET
};
#define gst_dvb_sub_enc_parent_class parent_class
G_DEFINE_TYPE (GstDvbSubEnc, gst_dvb_sub_enc, GST_TYPE_ELEMENT);
GST_ELEMENT_REGISTER_DEFINE_WITH_CODE (dvbsubenc, "dvbsubenc", GST_RANK_NONE,
GST_TYPE_DVB_SUB_ENC, GST_DEBUG_CATEGORY_INIT (gst_dvb_sub_enc_debug,
"dvbsubenc", 0, "DVB subtitle encoder");
);
static void gst_dvb_sub_enc_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static void gst_dvb_sub_enc_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static gboolean gst_dvb_sub_enc_src_event (GstPad * srcpad, GstObject * parent,
GstEvent * event);
static GstFlowReturn gst_dvb_sub_enc_chain (GstPad * pad, GstObject * parent,
GstBuffer * buf);
static void gst_dvb_sub_enc_finalize (GObject * gobject);
static gboolean gst_dvb_sub_enc_sink_event (GstPad * pad, GstObject * parent,
GstEvent * event);
static gboolean gst_dvb_sub_enc_sink_setcaps (GstPad * pad, GstCaps * caps);
static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("video/x-raw, format = (string) { AYUV }")
);
static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("subpicture/x-dvb")
);
GST_DEBUG_CATEGORY (gst_dvb_sub_enc_debug);
static void
gst_dvb_sub_enc_class_init (GstDvbSubEncClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
gobject_class->finalize = gst_dvb_sub_enc_finalize;
gst_element_class_add_static_pad_template (gstelement_class, &sink_template);
gst_element_class_add_static_pad_template (gstelement_class, &src_template);
gst_element_class_set_static_metadata (gstelement_class,
"DVB subtitle encoder", "Codec/Decoder/Video",
"Encodes AYUV video frames streams into DVB subtitles",
"Jan Schmidt <jan@centricular.com>");
gobject_class->set_property = gst_dvb_sub_enc_set_property;
gobject_class->get_property = gst_dvb_sub_enc_get_property;
/**
* GstDvbSubEnc:max-colours
*
* Set the maximum number of colours to output into the DVB subpictures.
* Good choices are 4, 16 or 256 - as they correspond to the 2-bit, 4-bit
* and 8-bit palette modes that the DVB subpicture encoding supports.
*/
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_MAX_COLOURS,
g_param_spec_int ("max-colours", "Maximum Colours",
"Maximum Number of Colours to output", 1, 256, DEFAULT_MAX_COLOURS,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
/**
* GstDvbSubEnc:ts-offset
*
* Advance or delay the output subpicture time-line. This is a
* convenience property for setting the src pad offset.
*/
g_object_class_install_property (gobject_class, PROP_TS_OFFSET,
g_param_spec_int64 ("ts-offset", "Subtitle Timestamp Offset",
"Apply an offset to incoming timestamps before output (in nanoseconds)",
G_MININT64, G_MAXINT64, 0,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
}
static void
gst_dvb_sub_enc_init (GstDvbSubEnc * enc)
{
GstPadTemplate *tmpl;
enc->sinkpad = gst_pad_new_from_static_template (&sink_template, "sink");
gst_pad_set_chain_function (enc->sinkpad,
GST_DEBUG_FUNCPTR (gst_dvb_sub_enc_chain));
gst_pad_set_event_function (enc->sinkpad,
GST_DEBUG_FUNCPTR (gst_dvb_sub_enc_sink_event));
gst_element_add_pad (GST_ELEMENT (enc), enc->sinkpad);
tmpl = gst_static_pad_template_get (&src_template);
enc->srcpad = gst_pad_new_from_template (tmpl, "src");
gst_pad_set_event_function (enc->srcpad,
GST_DEBUG_FUNCPTR (gst_dvb_sub_enc_src_event));
gst_pad_use_fixed_caps (enc->srcpad);
gst_object_unref (tmpl);
gst_element_add_pad (GST_ELEMENT (enc), enc->srcpad);
enc->max_colours = DEFAULT_MAX_COLOURS;
enc->ts_offset = DEFAULT_TS_OFFSET;
enc->current_end_time = GST_CLOCK_TIME_NONE;
}
static void
gst_dvb_sub_enc_finalize (GObject * gobject)
{
//GstDvbSubEnc *enc = GST_DVB_SUB_ENC (gobject);
G_OBJECT_CLASS (parent_class)->finalize (gobject);
}
static void
gst_dvb_sub_enc_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstDvbSubEnc *enc = GST_DVB_SUB_ENC (object);
switch (prop_id) {
case PROP_MAX_COLOURS:
g_value_set_int (value, enc->max_colours);
break;
case PROP_TS_OFFSET:
g_value_set_int64 (value, enc->ts_offset);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_dvb_sub_enc_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstDvbSubEnc *enc = GST_DVB_SUB_ENC (object);
switch (prop_id) {
case PROP_MAX_COLOURS:
enc->max_colours = g_value_get_int (value);
break;
case PROP_TS_OFFSET:
enc->ts_offset = g_value_get_int64 (value);
gst_pad_set_offset (enc->srcpad, enc->ts_offset);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static gboolean
gst_dvb_sub_enc_src_event (GstPad * pad, GstObject * parent, GstEvent * event)
{
gboolean res = FALSE;
switch (GST_EVENT_TYPE (event)) {
default:
res = gst_pad_event_default (pad, parent, event);
break;
}
return res;
}
static void
find_largest_subregion (guint8 * pixels, guint stride, guint pixel_stride,
gint width, gint height, guint * out_left, guint * out_right,
guint * out_top, guint * out_bottom)
{
guint left = width, right = 0, top = height, bottom = 0;
gint y, x;
guint8 *p = pixels;
for (y = 0; y < height; y++) {
gboolean visible_pixels = FALSE;
guint8 *l = p;
guint8 *r = p + (width - 1) * pixel_stride;
for (x = 0; x < width; x++) {
/* AYUV data = byte 0 = A */
if (l[0] != 0) {
visible_pixels = TRUE;
left = MIN (left, x);
}
if (r[0] != 0) {
visible_pixels = TRUE;
right = MAX (right, width - 1 - x);
}
l += pixel_stride;
r -= pixel_stride;
if (l >= r) /* Stop when we've scanned to the middle */
break;
}
if (visible_pixels) {
if (top > y)
top = y;
if (bottom < y)
bottom = y;
}
p += stride;
}
*out_left = left;
*out_right = right;
*out_top = top;
*out_bottom = bottom;
}
/* Create and map a new buffer containing the indicated subregion of the input
* image, returning the result in the 'out' GstVideoFrame */
static gboolean
create_cropped_frame (GstDvbSubEnc * enc, GstVideoFrame * in,
GstVideoFrame * out, guint x, guint y, guint width, guint height)
{
GstBuffer *cropped_buffer;
GstVideoInfo cropped_info;
guint8 *out_pixels, *in_pixels;
guint out_stride, in_stride, p_stride;
guint bottom = y + height;
g_return_val_if_fail (GST_VIDEO_INFO_FORMAT (&in->info) ==
GST_VIDEO_FORMAT_AYUV, FALSE);
gst_video_info_set_format (&cropped_info, GST_VIDEO_INFO_FORMAT (&in->info),
width, height);
cropped_buffer =
gst_buffer_new_allocate (NULL, GST_VIDEO_INFO_SIZE (&cropped_info), NULL);
if (!gst_video_frame_map (out, &cropped_info, cropped_buffer, GST_MAP_WRITE)) {
gst_buffer_unref (cropped_buffer);
return FALSE;
}
p_stride = GST_VIDEO_FRAME_COMP_PSTRIDE (in, 0);
in_stride = GST_VIDEO_FRAME_PLANE_STRIDE (in, 0);
in_pixels = GST_VIDEO_FRAME_PLANE_DATA (in, 0);
out_stride = GST_VIDEO_FRAME_PLANE_STRIDE (out, 0);
out_pixels = GST_VIDEO_FRAME_PLANE_DATA (out, 0);
in_pixels += y * in_stride + x * p_stride;
while (y < bottom) {
memcpy (out_pixels, in_pixels, width * p_stride);
in_pixels += in_stride;
out_pixels += out_stride;
y++;
}
/* By mapping the video frame no ref, it takes ownership of the buffer and it will be released
* on unmap (if the map call succeeds) */
gst_video_frame_unmap (out);
if (!gst_video_frame_map (out, &cropped_info, cropped_buffer,
GST_MAP_READ | GST_VIDEO_FRAME_MAP_FLAG_NO_REF)) {
gst_buffer_unref (cropped_buffer);
return FALSE;
}
return TRUE;
}
static GstFlowReturn
process_largest_subregion (GstDvbSubEnc * enc, GstVideoFrame * vframe)
{
GstFlowReturn ret = GST_FLOW_ERROR;
guint8 *pixels = GST_VIDEO_FRAME_PLANE_DATA (vframe, 0);
guint stride = GST_VIDEO_FRAME_PLANE_STRIDE (vframe, 0);
guint pixel_stride = GST_VIDEO_FRAME_COMP_PSTRIDE (vframe, 0);
guint left, right, top, bottom;
GstBuffer *ayuv8p_buffer;
GstVideoInfo ayuv8p_info;
GstVideoFrame cropped_frame, ayuv8p_frame;
guint32 num_colours;
GstClockTime end_ts = GST_CLOCK_TIME_NONE, duration;
find_largest_subregion (pixels, stride, pixel_stride, enc->in_info.width,
enc->in_info.height, &left, &right, &top, &bottom);
GST_LOG_OBJECT (enc, "Found subregion %u,%u -> %u,%u w %u, %u", left, top,
right, bottom, right - left + 1, bottom - top + 1);
if (!create_cropped_frame (enc, vframe, &cropped_frame, left, top,
right - left + 1, bottom - top + 1)) {
GST_WARNING_OBJECT (enc, "Failed to map frame conversion input buffer");
goto fail;
}
/* FIXME: RGB8P is the same size as what we're building, so this is fine,
* but it'd be better if we had an explicit paletted format for YUV8P */
gst_video_info_set_format (&ayuv8p_info, GST_VIDEO_FORMAT_RGB8P,
right - left + 1, bottom - top + 1);
ayuv8p_buffer =
gst_buffer_new_allocate (NULL, GST_VIDEO_INFO_SIZE (&ayuv8p_info), NULL);
/* Mapped without extra ref - the frame now owns the only ref */
if (!gst_video_frame_map (&ayuv8p_frame, &ayuv8p_info, ayuv8p_buffer,
GST_MAP_WRITE | GST_VIDEO_FRAME_MAP_FLAG_NO_REF)) {
GST_WARNING_OBJECT (enc, "Failed to map frame conversion output buffer");
gst_video_frame_unmap (&cropped_frame);
gst_buffer_unref (ayuv8p_buffer);
goto fail;
}
if (!gst_dvbsubenc_ayuv_to_ayuv8p (&cropped_frame, &ayuv8p_frame,
enc->max_colours, &num_colours)) {
GST_ERROR_OBJECT (enc,
"Failed to convert subpicture region to paletted 8-bit");
gst_video_frame_unmap (&cropped_frame);
gst_video_frame_unmap (&ayuv8p_frame);
goto skip;
}
gst_video_frame_unmap (&cropped_frame);
duration = GST_BUFFER_DURATION (vframe->buffer);
if (GST_CLOCK_TIME_IS_VALID (duration)) {
end_ts = GST_BUFFER_PTS (vframe->buffer);
if (GST_CLOCK_TIME_IS_VALID (end_ts)) {
end_ts += duration;
}
}
/* Encode output buffer and push it */
{
SubpictureRect s;
GstBuffer *packet;
s.frame = &ayuv8p_frame;
s.nb_colours = num_colours;
s.x = left;
s.y = top;
packet = gst_dvbenc_encode (enc->object_version & 0xF, 1, &s, 1);
if (packet == NULL) {
gst_video_frame_unmap (&ayuv8p_frame);
goto fail;
}
enc->object_version++;
gst_buffer_copy_into (packet, vframe->buffer, GST_BUFFER_COPY_METADATA, 0,
-1);
if (!GST_BUFFER_DTS_IS_VALID (packet))
GST_BUFFER_DTS (packet) = GST_BUFFER_PTS (packet);
ret = gst_pad_push (enc->srcpad, packet);
}
if (GST_CLOCK_TIME_IS_VALID (end_ts)) {
GST_LOG_OBJECT (enc, "Scheduling subtitle end packet for %" GST_TIME_FORMAT,
GST_TIME_ARGS (end_ts));
enc->current_end_time = end_ts;
}
gst_video_frame_unmap (&ayuv8p_frame);
return ret;
skip:
return GST_FLOW_OK;
fail:
return GST_FLOW_ERROR;
}
static GstFlowReturn
gst_dvb_sub_enc_generate_end_packet (GstDvbSubEnc * enc, GstClockTime pts)
{
GstBuffer *packet;
GstFlowReturn ret;
if (!GST_CLOCK_TIME_IS_VALID (enc->current_end_time))
return GST_FLOW_OK;
if (enc->current_end_time >= pts)
return GST_FLOW_OK; /* Didn't hit the end of the current subtitle yet */
GST_DEBUG_OBJECT (enc, "Outputting end of page at TS %" GST_TIME_FORMAT,
GST_TIME_ARGS (enc->current_end_time));
packet = gst_dvbenc_encode (enc->object_version & 0xF, 1, NULL, 0);
if (packet == NULL) {
GST_ELEMENT_ERROR (enc, STREAM, FAILED,
("Internal data stream error."),
("Failed to encode end of subtitle packet"));
return GST_FLOW_ERROR;
}
enc->object_version++;
GST_BUFFER_DTS (packet) = GST_BUFFER_PTS (packet) = enc->current_end_time;
enc->current_end_time = GST_CLOCK_TIME_NONE;
ret = gst_pad_push (enc->srcpad, packet);
return ret;
}
static GstFlowReturn
gst_dvb_sub_enc_chain (GstPad * pad, GstObject * parent, GstBuffer * buf)
{
GstFlowReturn ret = GST_FLOW_OK;
GstDvbSubEnc *enc = GST_DVB_SUB_ENC (parent);
GstVideoFrame vframe;
GstClockTime pts = GST_BUFFER_PTS (buf);
GST_DEBUG_OBJECT (enc, "Have buffer of size %" G_GSIZE_FORMAT ", ts %"
GST_TIME_FORMAT ", dur %" G_GINT64_FORMAT, gst_buffer_get_size (buf),
GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buf)), GST_BUFFER_DURATION (buf));
if (GST_CLOCK_TIME_IS_VALID (pts)) {
ret = gst_dvb_sub_enc_generate_end_packet (enc, pts);
if (ret != GST_FLOW_OK)
goto fail;
}
/* FIXME: Allow GstVideoOverlayComposition input, so we can directly encode the
* overlays passed */
/* Scan the input buffer for regions to encode */
/* FIXME: Could use the blob extents tracking code from OpenHMD here to collect
* multiple regions*/
if (!gst_video_frame_map (&vframe, &enc->in_info, buf, GST_MAP_READ)) {
GST_ERROR_OBJECT (enc, "Failed to map input buffer for reading");
ret = GST_FLOW_ERROR;
goto fail;
}
ret = process_largest_subregion (enc, &vframe);
gst_video_frame_unmap (&vframe);
fail:
gst_buffer_unref (buf);
return ret;
}
static gboolean
gst_dvb_sub_enc_sink_setcaps (GstPad * pad, GstCaps * caps)
{
GstDvbSubEnc *enc = GST_DVB_SUB_ENC (gst_pad_get_parent (pad));
gboolean ret = FALSE;
GstCaps *out_caps = NULL;
GST_DEBUG_OBJECT (enc, "setcaps called with %" GST_PTR_FORMAT, caps);
if (!gst_video_info_from_caps (&enc->in_info, caps)) {
GST_ERROR_OBJECT (enc, "Failed to parse input caps");
return FALSE;
}
out_caps = gst_caps_new_simple ("subpicture/x-dvb",
"width", G_TYPE_INT, enc->in_info.width,
"height", G_TYPE_INT, enc->in_info.height,
"framerate", GST_TYPE_FRACTION, enc->in_info.fps_n, enc->in_info.fps_d,
NULL);
if (!gst_pad_set_caps (enc->srcpad, out_caps)) {
GST_WARNING_OBJECT (enc, "failed setting downstream caps");
gst_caps_unref (out_caps);
goto beach;
}
gst_caps_unref (out_caps);
ret = TRUE;
beach:
gst_object_unref (enc);
return ret;
}
static gboolean
gst_dvb_sub_enc_sink_event (GstPad * pad, GstObject * parent, GstEvent * event)
{
GstDvbSubEnc *enc = GST_DVB_SUB_ENC (parent);
gboolean ret = FALSE;
GST_LOG_OBJECT (enc, "%s event", GST_EVENT_TYPE_NAME (event));
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_CAPS:
{
GstCaps *caps;
gst_event_parse_caps (event, &caps);
ret = gst_dvb_sub_enc_sink_setcaps (pad, caps);
gst_event_unref (event);
break;
}
case GST_EVENT_GAP:
{
GstClockTime start, duration;
gst_event_parse_gap (event, &start, &duration);
if (GST_CLOCK_TIME_IS_VALID (start)) {
if (GST_CLOCK_TIME_IS_VALID (duration))
start += duration;
/* we do not expect another buffer until after gap,
* so that is our position now */
GST_DEBUG_OBJECT (enc,
"Got GAP event, advancing time to %" GST_TIME_FORMAT,
GST_TIME_ARGS (start));
gst_dvb_sub_enc_generate_end_packet (enc, start);
} else {
GST_WARNING_OBJECT (enc, "Got GAP event with invalid position");
}
gst_event_unref (event);
ret = TRUE;
break;
}
case GST_EVENT_SEGMENT:
{
GstSegment seg;
gst_event_copy_segment (event, &seg);
ret = gst_pad_event_default (pad, parent, event);
break;
}
case GST_EVENT_FLUSH_STOP:{
enc->current_end_time = GST_CLOCK_TIME_NONE;
ret = gst_pad_event_default (pad, parent, event);
break;
}
default:{
ret = gst_pad_event_default (pad, parent, event);
break;
}
}
return ret;
}
static gboolean
plugin_init (GstPlugin * plugin)
{
return GST_ELEMENT_REGISTER (dvbsubenc, plugin);
}
GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
GST_VERSION_MINOR,
dvbsubenc,
"DVB subtitle parser and encoder", plugin_init,
VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN);