--- /dev/null
+/*
+ * payload_parsers.c
+ * Copyright (C) 2011 Janne Grunau
+ *
+ * Authors:
+ * Janne Grunau <janne.grunau@collabora.co.uk>
+ *
+ * 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., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "payload_parsers.h"
+#include <gst/base/gstbitreader.h>
+
+#define PICTURE_START_CODE 0x00000100
+#define GROUP_START_CODE 0x000001B8
+
+
+typedef struct Mpeg2PictureHeader
+{
+ guint16 temporal_reference;
+ guint8 picture_coding_type;
+ guint16 vbv_delay;
+
+ /* picture_coding_type == 2 || picture_coding_type */
+ guint8 full_pel_forward_vector;
+ guint8 forward_f_code;
+
+ /* picture_coding_type == 3 */
+ guint8 full_pel_backward_vector;
+ guint8 backward_f_code;
+} Mpeg2PictureHeader;
+
+
+static guint8 *
+find_start_code (guint32 * start_code, guint8 * buffer, guint8 * buffer_end)
+{
+ if (G_UNLIKELY (buffer == NULL) || G_UNLIKELY (buffer_end == NULL)
+ || G_UNLIKELY (start_code == NULL))
+ return NULL;
+
+ while (buffer <= buffer_end) {
+
+ *start_code <<= 8;
+ *start_code |= *buffer++;
+
+ if ((*start_code & 0xffffff00) == 0x00000100)
+ return buffer;
+ }
+
+ return NULL;
+}
+
+static gboolean
+parse_mpeg2_picture_header (Mpeg2PictureHeader * hdr, guint8 * buffer,
+ guint8 * buffer_end)
+{
+ GstBitReader br = GST_BIT_READER_INIT (buffer, buffer_end - buffer);
+
+ if (gst_bit_reader_get_remaining (&br) < 40)
+ return FALSE;
+
+ hdr->temporal_reference = gst_bit_reader_get_bits_uint16_unchecked (&br, 10);
+ hdr->picture_coding_type = gst_bit_reader_get_bits_uint8_unchecked (&br, 3);
+ hdr->vbv_delay = gst_bit_reader_get_bits_uint16_unchecked (&br, 16);
+
+ if (hdr->picture_coding_type == 2 || hdr->picture_coding_type == 3) {
+ hdr->full_pel_forward_vector =
+ gst_bit_reader_get_bits_uint8_unchecked (&br, 1);
+ hdr->forward_f_code = gst_bit_reader_get_bits_uint8_unchecked (&br, 3);
+ }
+ if (hdr->picture_coding_type == 3) {
+ hdr->full_pel_backward_vector =
+ gst_bit_reader_get_bits_uint8_unchecked (&br, 1);
+ hdr->backward_f_code = gst_bit_reader_get_bits_uint8_unchecked (&br, 3);
+ }
+ return TRUE;
+}
+
+gboolean
+gst_tsdemux_has_mpeg2_keyframe (guint32 * state,
+ MpegTSPacketizerPacket * packet)
+{
+
+ //guint32 i = 0;
+ guint8 *data = packet->payload;
+ guint8 *data_end = packet->data_end;
+
+ GST_LOG ("state: 0x%08x", *state);
+
+ while (data <= data_end) {
+
+ data = find_start_code (state, data, data_end);
+
+ if (!data)
+ return FALSE;
+
+ GST_LOG ("found start code: 0x%08x", *state);
+
+ if (*state == GROUP_START_CODE) {
+ GST_DEBUG ("found group start code");
+ *state = 0xffffffff;
+ return TRUE;
+ } else if (*state == PICTURE_START_CODE) {
+ Mpeg2PictureHeader hdr = { 0 };
+ gboolean success;
+ *state = 0xffffffff;
+ success = parse_mpeg2_picture_header (&hdr, data, data_end);
+ GST_DEBUG ("found picture start code, %sparsed, picture coding type: %d",
+ success ? "" : "not ", hdr.picture_coding_type);
+ return success && hdr.picture_coding_type == 1;
+ }
+ }
+
+ return FALSE;
+}
--- /dev/null
+/*
+ * payload_parsers.h
+ * Copyright (C) 2011 Janne Grunau
+ *
+ * Authors:
+ * Janne Grunau <janne.grunau@collabora.co.uk>
+ *
+ * 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., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "mpegtspacketizer.h"
+
+typedef gboolean (*payload_parse_keyframe) (guint32 *state, MpegTSPacketizerPacket * packet);
+
+gboolean
+gst_tsdemux_has_mpeg2_keyframe (guint32 *state, MpegTSPacketizerPacket * packet);
#include "gstmpegdesc.h"
#include "gstmpegdefs.h"
#include "mpegtspacketizer.h"
+#include "payload_parsers.h"
/* latency in mseconds */
#define TS_LATENCY 700
return res;
}
-
-/* performs a accurate seek to the last packet with pts < seektime */
+/* performs a accurate/key_unit seek */
static GstFlowReturn
-gst_ts_demux_perform_accurate_seek (MpegTSBase * base, GstClockTime seektime,
- TSPcrOffset * pcroffset, gint64 length, gint16 pid)
+gst_ts_demux_perform_auxiliary_seek (MpegTSBase * base, GstClockTime seektime,
+ TSPcrOffset * pcroffset, gint64 length, gint16 pid, GstSeekFlags flags,
+ payload_parse_keyframe auxiliary_seek_fn)
{
GstTSDemux *demux = (GstTSDemux *) base;
GstFlowReturn res = GST_FLOW_ERROR;
gboolean done = FALSE;
+ gboolean found_keyframe = FALSE, found_accurate = FALSE;
GstBuffer *buf;
MpegTSPacketizerPacket packet;
MpegTSPacketizerPacketReturn pret;
gint64 offset = pcroffset->offset;
gint64 scan_offset = MIN (length, 50 * MPEGTS_MAX_PACKETSIZE);
+ guint32 state = 0xffffffff;
+ TSPcrOffset key_pos = { 0 };
+ GST_DEBUG ("auxiliary seek for %" GST_TIME_FORMAT " from offset: %"
+ G_GINT64_FORMAT " in %" G_GINT64_FORMAT " bytes for PID: %d "
+ "%s %s", GST_TIME_ARGS (seektime), pcroffset->offset, length, pid,
+ (flags & GST_SEEK_FLAG_ACCURATE) ? "accurate" : "",
+ (flags & GST_SEEK_FLAG_KEY_UNIT) ? "key_unit" : "");
- GST_DEBUG ("accurate seek for %" GST_TIME_FORMAT " from offset: %"
- G_GINT64_FORMAT " in %" G_GINT64_FORMAT " bytes for PID: %d",
- GST_TIME_ARGS (seektime), pcroffset->offset, length, pid);
+ if ((flags & GST_SEEK_FLAG_KEY_UNIT) && !auxiliary_seek_fn) {
+ GST_ERROR ("key_unit seek for unkown video codec");
+ goto beach;
+ }
mpegts_packetizer_flush (base->packetizer);
" at offset: %" G_GINT64_FORMAT, packet.pid,
GST_TIME_ARGS (packet.pcr), packet.offset);
- if (packet.payload != NULL && packet.payload_unit_start_indicator
- && packet.pid == pid) {
- guint64 pts = 0;
+ if (packet.payload != NULL && packet.pid == pid) {
- res = gst_ts_demux_parse_pes_header_pts (demux, &packet, &pts);
- if (res == GST_FLOW_OK) {
- GstClockTime time = calculate_gsttime (pcroffset, pts * 300);
+ if (packet.payload_unit_start_indicator) {
+ guint64 pts = 0;
+ res = gst_ts_demux_parse_pes_header_pts (demux, &packet, &pts);
+ if (res == GST_FLOW_OK) {
+ GstClockTime time = calculate_gsttime (pcroffset, pts * 300);
- GST_DEBUG ("packet has PTS: %" GST_TIME_FORMAT,
+ GST_DEBUG ("packet has PTS: %" GST_TIME_FORMAT,
GST_TIME_ARGS (time));
- if (time <= seektime) {
- pcroffset->gsttime = time;
- pcroffset->pcr = packet.pcr;
- pcroffset->offset = packet.offset;
+ if (time <= seektime) {
+ pcroffset->gsttime = time;
+ pcroffset->pcr = packet.pcr;
+ pcroffset->offset = packet.offset;
+ } else
+ found_accurate = TRUE;
} else
- done = TRUE;
- } else
- goto next;
+ goto next;
+ /* reset state for new packet */
+ state = 0xffffffff;
+ }
+
+ if (flags & GST_SEEK_FLAG_KEY_UNIT) {
+ gboolean is_keyframe = auxiliary_seek_fn (&state, &packet);
+ if (is_keyframe) {
+ found_keyframe = TRUE;
+ key_pos = *pcroffset;
+ GST_DEBUG ("found keyframe: time: %" GST_TIME_FORMAT " pcr: %"
+ GST_TIME_FORMAT " offset %" G_GINT64_FORMAT,
+ GST_TIME_ARGS (pcroffset->gsttime),
+ GST_TIME_ARGS (pcroffset->pcr), pcroffset->offset);
+ }
+ }
+ }
+ switch (flags & (GST_SEEK_FLAG_ACCURATE | GST_SEEK_FLAG_KEY_UNIT)) {
+ case GST_SEEK_FLAG_ACCURATE | GST_SEEK_FLAG_KEY_UNIT:
+ done = found_accurate && found_keyframe;
+ *pcroffset = key_pos;
+ break;
+ case GST_SEEK_FLAG_ACCURATE:
+ done = found_accurate;
+ break;
+ case GST_SEEK_FLAG_KEY_UNIT:
+ done = found_keyframe;
+ break;
}
next:
mpegts_packetizer_clear_packet (base->packetizer, &packet);
scan_offset += 50 * MPEGTS_MAX_PACKETSIZE;
}
+ if (done)
+ res = GST_FLOW_OK;
+
beach:
mpegts_packetizer_flush (base->packetizer);
return res;
GST_DEBUG ("seeking finished after %d loops", loop_cnt);
- if (segment->flags & GST_SEEK_FLAG_ACCURATE) {
+ if (segment->flags & GST_SEEK_FLAG_ACCURATE
+ || segment->flags & GST_SEEK_FLAG_KEY_UNIT) {
+ payload_parse_keyframe keyframe_seek = NULL;
MpegTSBaseProgram *program = demux->program;
if (program->streams[pid]) {
switch (program->streams[pid]->stream_type) {
case ST_VIDEO_MPEG1:
case ST_VIDEO_MPEG2:
+ keyframe_seek = gst_tsdemux_has_mpeg2_keyframe;
+ break;
case ST_VIDEO_MPEG4:
case ST_VIDEO_H264:
case ST_VIDEO_DIRAC:
seekpcroffset.pcr = pcr_start.pcr;
seekpcroffset.offset = pcr_start.offset;
res =
- gst_ts_demux_perform_accurate_seek (base, seektime, &seekpcroffset,
- pcr_stop.offset - pcr_start.offset, pid);
+ gst_ts_demux_perform_auxiliary_seek (base, seektime, &seekpcroffset,
+ pcr_stop.offset - pcr_start.offset, pid, segment->flags, keyframe_seek);
}
segment->last_stop = seekpcroffset.gsttime;
accurate = flags & GST_SEEK_FLAG_ACCURATE;
flush = flags & GST_SEEK_FLAG_FLUSH;
- if (flags & (GST_SEEK_FLAG_KEY_UNIT | GST_SEEK_FLAG_SEGMENT |
- GST_SEEK_FLAG_SKIP)) {
+ if (flags & (GST_SEEK_FLAG_SEGMENT | GST_SEEK_FLAG_SKIP)) {
GST_WARNING ("seek flags 0x%x are not supported", (int) flags);
goto done;
}
projects / platform / upstream / gstreamer.git / commitdiff