ffmpeg/libavformat/mux.c
Anton Khirnov 8de1ee9f72 lavf: deprecate compute_pkt_fields2
All encoders set pts and dts properly now (and have been doing that for
a while), so there is no good reason to do any timestamp guessing in the
muxer.

The newly added AVStreamInternal will be later used for storing all the
private fields currently living in AVStream.
2015-11-09 07:50:55 +01:00

730 lines
23 KiB
C

/*
* muxing functions for use within Libav
* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avformat.h"
#include "avio_internal.h"
#include "internal.h"
#include "libavcodec/internal.h"
#include "libavcodec/bytestream.h"
#include "libavutil/opt.h"
#include "libavutil/dict.h"
#include "libavutil/pixdesc.h"
#include "metadata.h"
#include "id3v2.h"
#include "libavutil/avassert.h"
#include "libavutil/avstring.h"
#include "libavutil/internal.h"
#include "libavutil/mathematics.h"
#include "libavutil/parseutils.h"
#include "libavutil/time.h"
#include "riff.h"
#include "audiointerleave.h"
#include "url.h"
#include <stdarg.h>
#if CONFIG_NETWORK
#include "network.h"
#endif
#undef NDEBUG
#include <assert.h>
/**
* @file
* muxing functions for use within Libav
*/
static int validate_codec_tag(AVFormatContext *s, AVStream *st)
{
const AVCodecTag *avctag;
int n;
enum AVCodecID id = AV_CODEC_ID_NONE;
unsigned int tag = 0;
/**
* Check that tag + id is in the table
* If neither is in the table -> OK
* If tag is in the table with another id -> FAIL
* If id is in the table with another tag -> FAIL unless strict < normal
*/
for (n = 0; s->oformat->codec_tag[n]; n++) {
avctag = s->oformat->codec_tag[n];
while (avctag->id != AV_CODEC_ID_NONE) {
if (avpriv_toupper4(avctag->tag) == avpriv_toupper4(st->codec->codec_tag)) {
id = avctag->id;
if (id == st->codec->codec_id)
return 1;
}
if (avctag->id == st->codec->codec_id)
tag = avctag->tag;
avctag++;
}
}
if (id != AV_CODEC_ID_NONE)
return 0;
if (tag && (s->strict_std_compliance >= FF_COMPLIANCE_NORMAL))
return 0;
return 1;
}
static int init_muxer(AVFormatContext *s, AVDictionary **options)
{
int ret = 0, i;
AVStream *st;
AVDictionary *tmp = NULL;
AVCodecContext *codec = NULL;
AVOutputFormat *of = s->oformat;
const AVCodecDescriptor *desc;
if (options)
av_dict_copy(&tmp, *options, 0);
if ((ret = av_opt_set_dict(s, &tmp)) < 0)
goto fail;
#if FF_API_LAVF_BITEXACT
if (s->nb_streams && s->streams[0]->codec->flags & AV_CODEC_FLAG_BITEXACT)
s->flags |= AVFMT_FLAG_BITEXACT;
#endif
// some sanity checks
if (s->nb_streams == 0 && !(of->flags & AVFMT_NOSTREAMS)) {
av_log(s, AV_LOG_ERROR, "no streams\n");
ret = AVERROR(EINVAL);
goto fail;
}
for (i = 0; i < s->nb_streams; i++) {
st = s->streams[i];
codec = st->codec;
#if FF_API_LAVF_CODEC_TB
FF_DISABLE_DEPRECATION_WARNINGS
if (!st->time_base.num && codec->time_base.num) {
av_log(s, AV_LOG_WARNING, "Using AVStream.codec.time_base as a "
"timebase hint to the muxer is deprecated. Set "
"AVStream.time_base instead.\n");
avpriv_set_pts_info(st, 64, codec->time_base.num, codec->time_base.den);
}
FF_ENABLE_DEPRECATION_WARNINGS
#endif
if (!st->time_base.num) {
/* fall back on the default timebase values */
if (codec->codec_type == AVMEDIA_TYPE_AUDIO && codec->sample_rate)
avpriv_set_pts_info(st, 64, 1, codec->sample_rate);
else
avpriv_set_pts_info(st, 33, 1, 90000);
}
switch (codec->codec_type) {
case AVMEDIA_TYPE_AUDIO:
if (codec->sample_rate <= 0) {
av_log(s, AV_LOG_ERROR, "sample rate not set\n");
ret = AVERROR(EINVAL);
goto fail;
}
if (!codec->block_align)
codec->block_align = codec->channels *
av_get_bits_per_sample(codec->codec_id) >> 3;
break;
case AVMEDIA_TYPE_VIDEO:
if ((codec->width <= 0 || codec->height <= 0) &&
!(of->flags & AVFMT_NODIMENSIONS)) {
av_log(s, AV_LOG_ERROR, "dimensions not set\n");
ret = AVERROR(EINVAL);
goto fail;
}
if (av_cmp_q(st->sample_aspect_ratio,
codec->sample_aspect_ratio)) {
if (st->sample_aspect_ratio.num != 0 &&
st->sample_aspect_ratio.den != 0 &&
codec->sample_aspect_ratio.den != 0 &&
codec->sample_aspect_ratio.den != 0) {
av_log(s, AV_LOG_ERROR, "Aspect ratio mismatch between muxer "
"(%d/%d) and encoder layer (%d/%d)\n",
st->sample_aspect_ratio.num, st->sample_aspect_ratio.den,
codec->sample_aspect_ratio.num,
codec->sample_aspect_ratio.den);
ret = AVERROR(EINVAL);
goto fail;
}
}
break;
}
desc = avcodec_descriptor_get(codec->codec_id);
if (desc && desc->props & AV_CODEC_PROP_REORDER)
st->internal->reorder = 1;
if (of->codec_tag) {
if (codec->codec_tag &&
codec->codec_id == AV_CODEC_ID_RAWVIDEO &&
!av_codec_get_tag(of->codec_tag, codec->codec_id) &&
!validate_codec_tag(s, st)) {
// the current rawvideo encoding system ends up setting
// the wrong codec_tag for avi, we override it here
codec->codec_tag = 0;
}
if (codec->codec_tag) {
if (!validate_codec_tag(s, st)) {
char tagbuf[32];
av_get_codec_tag_string(tagbuf, sizeof(tagbuf), codec->codec_tag);
av_log(s, AV_LOG_ERROR,
"Tag %s/0x%08x incompatible with output codec id '%d'\n",
tagbuf, codec->codec_tag, codec->codec_id);
ret = AVERROR_INVALIDDATA;
goto fail;
}
} else
codec->codec_tag = av_codec_get_tag(of->codec_tag, codec->codec_id);
}
if (of->flags & AVFMT_GLOBALHEADER &&
!(codec->flags & AV_CODEC_FLAG_GLOBAL_HEADER))
av_log(s, AV_LOG_WARNING,
"Codec for stream %d does not use global headers "
"but container format requires global headers\n", i);
if (codec->codec_type != AVMEDIA_TYPE_ATTACHMENT)
s->internal->nb_interleaved_streams++;
}
if (!s->priv_data && of->priv_data_size > 0) {
s->priv_data = av_mallocz(of->priv_data_size);
if (!s->priv_data) {
ret = AVERROR(ENOMEM);
goto fail;
}
if (of->priv_class) {
*(const AVClass **)s->priv_data = of->priv_class;
av_opt_set_defaults(s->priv_data);
if ((ret = av_opt_set_dict(s->priv_data, &tmp)) < 0)
goto fail;
}
}
/* set muxer identification string */
if (!(s->flags & AVFMT_FLAG_BITEXACT)) {
av_dict_set(&s->metadata, "encoder", LIBAVFORMAT_IDENT, 0);
}
if (options) {
av_dict_free(options);
*options = tmp;
}
return 0;
fail:
av_dict_free(&tmp);
return ret;
}
int avformat_write_header(AVFormatContext *s, AVDictionary **options)
{
int ret = 0;
if (ret = init_muxer(s, options))
return ret;
if (s->oformat->write_header) {
ret = s->oformat->write_header(s);
if (ret < 0)
return ret;
}
if (s->avoid_negative_ts == AVFMT_AVOID_NEG_TS_AUTO) {
if (s->oformat->flags & (AVFMT_TS_NEGATIVE | AVFMT_NOTIMESTAMPS)) {
s->avoid_negative_ts = 0;
} else
s->avoid_negative_ts = AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE;
}
return 0;
}
#if FF_API_COMPUTE_PKT_FIELDS2
//FIXME merge with compute_pkt_fields
static int compute_pkt_fields2(AVFormatContext *s, AVStream *st, AVPacket *pkt)
{
int delay = FFMAX(st->codec->has_b_frames, !!st->codec->max_b_frames);
int num, den, i;
if (!s->internal->missing_ts_warning &&
!(s->oformat->flags & AVFMT_NOTIMESTAMPS) &&
(pkt->pts == AV_NOPTS_VALUE || pkt->dts == AV_NOPTS_VALUE)) {
av_log(s, AV_LOG_WARNING,
"Timestamps are unset in a packet for stream %d. "
"This is deprecated and will stop working in the future. "
"Fix your code to set the timestamps properly\n", st->index);
s->internal->missing_ts_warning = 1;
}
av_log(s, AV_LOG_TRACE, "compute_pkt_fields2: pts:%" PRId64 " dts:%" PRId64 " cur_dts:%" PRId64 " b:%d size:%d st:%d\n",
pkt->pts, pkt->dts, st->cur_dts, delay, pkt->size, pkt->stream_index);
/* if(pkt->pts == AV_NOPTS_VALUE && pkt->dts == AV_NOPTS_VALUE)
* return AVERROR(EINVAL);*/
/* duration field */
if (pkt->duration == 0) {
ff_compute_frame_duration(s, &num, &den, st, NULL, pkt);
if (den && num) {
pkt->duration = av_rescale(1, num * (int64_t)st->time_base.den * st->codec->ticks_per_frame, den * (int64_t)st->time_base.num);
}
}
if (pkt->pts == AV_NOPTS_VALUE && pkt->dts != AV_NOPTS_VALUE && delay == 0)
pkt->pts = pkt->dts;
//calculate dts from pts
if (pkt->pts != AV_NOPTS_VALUE && pkt->dts == AV_NOPTS_VALUE && delay <= MAX_REORDER_DELAY) {
st->pts_buffer[0] = pkt->pts;
for (i = 1; i < delay + 1 && st->pts_buffer[i] == AV_NOPTS_VALUE; i++)
st->pts_buffer[i] = pkt->pts + (i - delay - 1) * pkt->duration;
for (i = 0; i<delay && st->pts_buffer[i] > st->pts_buffer[i + 1]; i++)
FFSWAP(int64_t, st->pts_buffer[i], st->pts_buffer[i + 1]);
pkt->dts = st->pts_buffer[0];
}
if (st->cur_dts && st->cur_dts != AV_NOPTS_VALUE &&
((!(s->oformat->flags & AVFMT_TS_NONSTRICT) &&
st->cur_dts >= pkt->dts) || st->cur_dts > pkt->dts)) {
av_log(s, AV_LOG_ERROR,
"Application provided invalid, non monotonically increasing dts to muxer in stream %d: %" PRId64 " >= %" PRId64 "\n",
st->index, st->cur_dts, pkt->dts);
return AVERROR(EINVAL);
}
if (pkt->dts != AV_NOPTS_VALUE && pkt->pts != AV_NOPTS_VALUE && pkt->pts < pkt->dts) {
av_log(s, AV_LOG_ERROR,
"pts %" PRId64 " < dts %" PRId64 " in stream %d\n",
pkt->pts, pkt->dts,
st->index);
return AVERROR(EINVAL);
}
av_log(s, AV_LOG_TRACE, "av_write_frame: pts2:%"PRId64" dts2:%"PRId64"\n",
pkt->pts, pkt->dts);
st->cur_dts = pkt->dts;
return 0;
}
#endif
/*
* FIXME: this function should NEVER get undefined pts/dts beside when the
* AVFMT_NOTIMESTAMPS is set.
* Those additional safety checks should be dropped once the correct checks
* are set in the callers.
*/
static int write_packet(AVFormatContext *s, AVPacket *pkt)
{
int ret;
if (s->avoid_negative_ts > 0) {
AVRational time_base = s->streams[pkt->stream_index]->time_base;
int64_t offset = 0;
if (s->internal->offset == AV_NOPTS_VALUE && pkt->dts != AV_NOPTS_VALUE &&
(pkt->dts < 0 || s->avoid_negative_ts == AVFMT_AVOID_NEG_TS_MAKE_ZERO)) {
s->internal->offset = -pkt->dts;
s->internal->offset_timebase = time_base;
}
if (s->internal->offset != AV_NOPTS_VALUE)
offset = av_rescale_q(s->internal->offset, s->internal->offset_timebase, time_base);
if (pkt->dts != AV_NOPTS_VALUE)
pkt->dts += offset;
if (pkt->pts != AV_NOPTS_VALUE)
pkt->pts += offset;
if (pkt->dts != AV_NOPTS_VALUE && pkt->dts < 0) {
av_log(s, AV_LOG_WARNING,
"Packets poorly interleaved, failed to avoid negative "
"timestamp %"PRId64" in stream %d.\n"
"Try -max_interleave_delta 0 as a possible workaround.\n",
pkt->dts, pkt->stream_index);
}
}
ret = s->oformat->write_packet(s, pkt);
if (s->pb && ret >= 0) {
if (s->flags & AVFMT_FLAG_FLUSH_PACKETS)
avio_flush(s->pb);
if (s->pb->error < 0)
ret = s->pb->error;
}
return ret;
}
static int check_packet(AVFormatContext *s, AVPacket *pkt)
{
if (!pkt)
return 0;
if (pkt->stream_index < 0 || pkt->stream_index >= s->nb_streams) {
av_log(s, AV_LOG_ERROR, "Invalid packet stream index: %d\n",
pkt->stream_index);
return AVERROR(EINVAL);
}
if (s->streams[pkt->stream_index]->codec->codec_type == AVMEDIA_TYPE_ATTACHMENT) {
av_log(s, AV_LOG_ERROR, "Received a packet for an attachment stream.\n");
return AVERROR(EINVAL);
}
return 0;
}
static int prepare_input_packet(AVFormatContext *s, AVPacket *pkt)
{
int ret;
ret = check_packet(s, pkt);
if (ret < 0)
return ret;
#if !FF_API_COMPUTE_PKT_FIELDS2
/* sanitize the timestamps */
if (!(s->oformat->flags & AVFMT_NOTIMESTAMPS)) {
AVStream *st = s->streams[pkt->stream_index];
/* when there is no reordering (so dts is equal to pts), but
* only one of them is set, set the other as well */
if (!st->internal->reorder) {
if (pkt->pts == AV_NOPTS_VALUE && pkt->dts != AV_NOPTS_VALUE)
pkt->pts = pkt->dts;
if (pkt->dts == AV_NOPTS_VALUE && pkt->pts != AV_NOPTS_VALUE)
pkt->dts = pkt->pts;
}
/* check that the timestamps are set */
if (pkt->pts == AV_NOPTS_VALUE || pkt->dts == AV_NOPTS_VALUE) {
av_log(s, AV_LOG_ERROR,
"Timestamps are unset in a packet for stream %d\n", st->index);
return AVERROR(EINVAL);
}
/* check that the dts are increasing (or at least non-decreasing,
* if the format allows it */
if (st->cur_dts != AV_NOPTS_VALUE &&
((!(s->oformat->flags & AVFMT_TS_NONSTRICT) && st->cur_dts >= pkt->dts) ||
st->cur_dts > pkt->dts)) {
av_log(s, AV_LOG_ERROR,
"Application provided invalid, non monotonically increasing "
"dts to muxer in stream %d: %" PRId64 " >= %" PRId64 "\n",
st->index, st->cur_dts, pkt->dts);
return AVERROR(EINVAL);
}
if (pkt->pts < pkt->dts) {
av_log(s, AV_LOG_ERROR, "pts %" PRId64 " < dts %" PRId64 " in stream %d\n",
pkt->pts, pkt->dts, st->index);
return AVERROR(EINVAL);
}
}
#endif
return 0;
}
int av_write_frame(AVFormatContext *s, AVPacket *pkt)
{
int ret;
ret = prepare_input_packet(s, pkt);
if (ret < 0)
return ret;
if (!pkt) {
if (s->oformat->flags & AVFMT_ALLOW_FLUSH)
return s->oformat->write_packet(s, pkt);
return 1;
}
#if FF_API_COMPUTE_PKT_FIELDS2
ret = compute_pkt_fields2(s, s->streams[pkt->stream_index], pkt);
if (ret < 0 && !(s->oformat->flags & AVFMT_NOTIMESTAMPS))
return ret;
#endif
ret = write_packet(s, pkt);
if (ret >= 0)
s->streams[pkt->stream_index]->nb_frames++;
return ret;
}
int ff_interleave_add_packet(AVFormatContext *s, AVPacket *pkt,
int (*compare)(AVFormatContext *, AVPacket *, AVPacket *))
{
int ret;
AVPacketList **next_point, *this_pktl;
this_pktl = av_mallocz(sizeof(AVPacketList));
if (!this_pktl)
return AVERROR(ENOMEM);
if ((ret = av_packet_ref(&this_pktl->pkt, pkt)) < 0) {
av_free(this_pktl);
return ret;
}
if (s->streams[pkt->stream_index]->last_in_packet_buffer) {
next_point = &(s->streams[pkt->stream_index]->last_in_packet_buffer->next);
} else
next_point = &s->internal->packet_buffer;
if (*next_point) {
if (compare(s, &s->internal->packet_buffer_end->pkt, pkt)) {
while (!compare(s, &(*next_point)->pkt, pkt))
next_point = &(*next_point)->next;
goto next_non_null;
} else {
next_point = &(s->internal->packet_buffer_end->next);
}
}
assert(!*next_point);
s->internal->packet_buffer_end = this_pktl;
next_non_null:
this_pktl->next = *next_point;
s->streams[pkt->stream_index]->last_in_packet_buffer =
*next_point = this_pktl;
av_packet_unref(pkt);
return 0;
}
static int interleave_compare_dts(AVFormatContext *s, AVPacket *next,
AVPacket *pkt)
{
AVStream *st = s->streams[pkt->stream_index];
AVStream *st2 = s->streams[next->stream_index];
int comp = av_compare_ts(next->dts, st2->time_base, pkt->dts,
st->time_base);
if (comp == 0)
return pkt->stream_index < next->stream_index;
return comp > 0;
}
int ff_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,
AVPacket *pkt, int flush)
{
AVPacketList *pktl;
int stream_count = 0;
int i, ret;
if (pkt) {
if ((ret = ff_interleave_add_packet(s, pkt, interleave_compare_dts)) < 0)
return ret;
}
if (s->max_interleave_delta > 0 && s->internal->packet_buffer && !flush) {
AVPacket *top_pkt = &s->internal->packet_buffer->pkt;
int64_t delta_dts = INT64_MIN;
int64_t top_dts = av_rescale_q(top_pkt->dts,
s->streams[top_pkt->stream_index]->time_base,
AV_TIME_BASE_Q);
for (i = 0; i < s->nb_streams; i++) {
int64_t last_dts;
const AVPacketList *last = s->streams[i]->last_in_packet_buffer;
if (!last)
continue;
last_dts = av_rescale_q(last->pkt.dts,
s->streams[i]->time_base,
AV_TIME_BASE_Q);
delta_dts = FFMAX(delta_dts, last_dts - top_dts);
stream_count++;
}
if (delta_dts > s->max_interleave_delta) {
av_log(s, AV_LOG_DEBUG,
"Delay between the first packet and last packet in the "
"muxing queue is %"PRId64" > %"PRId64": forcing output\n",
delta_dts, s->max_interleave_delta);
flush = 1;
}
} else {
for (i = 0; i < s->nb_streams; i++)
stream_count += !!s->streams[i]->last_in_packet_buffer;
}
if (stream_count && (s->internal->nb_interleaved_streams == stream_count || flush)) {
pktl = s->internal->packet_buffer;
*out = pktl->pkt;
s->internal->packet_buffer = pktl->next;
if (!s->internal->packet_buffer)
s->internal->packet_buffer_end = NULL;
if (s->streams[out->stream_index]->last_in_packet_buffer == pktl)
s->streams[out->stream_index]->last_in_packet_buffer = NULL;
av_freep(&pktl);
return 1;
} else {
av_init_packet(out);
return 0;
}
}
/**
* Interleave an AVPacket correctly so it can be muxed.
* @param out the interleaved packet will be output here
* @param in the input packet
* @param flush 1 if no further packets are available as input and all
* remaining packets should be output
* @return 1 if a packet was output, 0 if no packet could be output,
* < 0 if an error occurred
*/
static int interleave_packet(AVFormatContext *s, AVPacket *out, AVPacket *in, int flush)
{
if (s->oformat->interleave_packet) {
int ret = s->oformat->interleave_packet(s, out, in, flush);
if (in)
av_packet_unref(in);
return ret;
} else
return ff_interleave_packet_per_dts(s, out, in, flush);
}
int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
{
int ret, flush = 0;
ret = prepare_input_packet(s, pkt);
if (ret < 0)
goto fail;
if (pkt) {
AVStream *st = s->streams[pkt->stream_index];
av_log(s, AV_LOG_TRACE, "av_interleaved_write_frame size:%d dts:%" PRId64 " pts:%" PRId64 "\n",
pkt->size, pkt->dts, pkt->pts);
#if FF_API_COMPUTE_PKT_FIELDS2
if ((ret = compute_pkt_fields2(s, st, pkt)) < 0 && !(s->oformat->flags & AVFMT_NOTIMESTAMPS))
goto fail;
#endif
if (pkt->dts == AV_NOPTS_VALUE && !(s->oformat->flags & AVFMT_NOTIMESTAMPS)) {
ret = AVERROR(EINVAL);
goto fail;
}
} else {
av_log(s, AV_LOG_TRACE, "av_interleaved_write_frame FLUSH\n");
flush = 1;
}
for (;; ) {
AVPacket opkt;
int ret = interleave_packet(s, &opkt, pkt, flush);
if (pkt) {
memset(pkt, 0, sizeof(*pkt));
av_init_packet(pkt);
pkt = NULL;
}
if (ret <= 0) //FIXME cleanup needed for ret<0 ?
return ret;
ret = write_packet(s, &opkt);
if (ret >= 0)
s->streams[opkt.stream_index]->nb_frames++;
av_packet_unref(&opkt);
if (ret < 0)
return ret;
}
fail:
av_packet_unref(pkt);
return ret;
}
int av_write_trailer(AVFormatContext *s)
{
int ret, i;
for (;; ) {
AVPacket pkt;
ret = interleave_packet(s, &pkt, NULL, 1);
if (ret < 0) //FIXME cleanup needed for ret<0 ?
goto fail;
if (!ret)
break;
ret = write_packet(s, &pkt);
if (ret >= 0)
s->streams[pkt.stream_index]->nb_frames++;
av_packet_unref(&pkt);
if (ret < 0)
goto fail;
}
if (s->oformat->write_trailer)
ret = s->oformat->write_trailer(s);
if (!(s->oformat->flags & AVFMT_NOFILE) && s->pb)
avio_flush(s->pb);
fail:
for (i = 0; i < s->nb_streams; i++) {
av_freep(&s->streams[i]->priv_data);
av_freep(&s->streams[i]->index_entries);
}
if (s->oformat->priv_class)
av_opt_free(s->priv_data);
av_freep(&s->priv_data);
return ret;
}
int ff_write_chained(AVFormatContext *dst, int dst_stream, AVPacket *pkt,
AVFormatContext *src)
{
AVPacket local_pkt;
local_pkt = *pkt;
local_pkt.stream_index = dst_stream;
if (pkt->pts != AV_NOPTS_VALUE)
local_pkt.pts = av_rescale_q(pkt->pts,
src->streams[pkt->stream_index]->time_base,
dst->streams[dst_stream]->time_base);
if (pkt->dts != AV_NOPTS_VALUE)
local_pkt.dts = av_rescale_q(pkt->dts,
src->streams[pkt->stream_index]->time_base,
dst->streams[dst_stream]->time_base);
return av_write_frame(dst, &local_pkt);
}