virtualenv/FFmpeg
1
0
Fork 0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-12 19:18:44 +02:00
Code Issues Releases Activity
83bf40f3cf
FFmpeg/libavformat/mux.c
Rodger Combs 1f6d7eb470
lavf: add a flag to enable/disable automatic bitstream filtering 
This is mostly useful for muxers that wrap other muxers, such as dashenc
and segment. The actual duplicated bitstream filtering is largely harmless,
but delaying the header can cause problems when the muxer intended the header
to be written to a separate file.
2016-09-12 21:50:32 -05:00

1394 lines
46 KiB
C
Raw Blame History

/*
* muxing functions for use within FFmpeg
* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; 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 "libavutil/timestamp.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
/**
* @file
* muxing functions for use within libavformat
*/
/* fraction handling */
/**
* f = val + (num / den) + 0.5.
*
* 'num' is normalized so that it is such as 0 <= num < den.
*
* @param f fractional number
* @param val integer value
* @param num must be >= 0
* @param den must be >= 1
*/
static void frac_init(FFFrac *f, int64_t val, int64_t num, int64_t den)
{
num += (den >> 1);
if (num >= den) {
val += num / den;
num = num % den;
}
f->val = val;
f->num = num;
f->den = den;
}
/**
* Fractional addition to f: f = f + (incr / f->den).
*
* @param f fractional number
* @param incr increment, can be positive or negative
*/
static void frac_add(FFFrac *f, int64_t incr)
{
int64_t num, den;
num = f->num + incr;
den = f->den;
if (num < 0) {
f->val += num / den;
num = num % den;
if (num < 0) {
num += den;
f->val--;
}
} else if (num >= den) {
f->val += num / den;
num = num % den;
}
f->num = num;
}
AVRational ff_choose_timebase(AVFormatContext *s, AVStream *st, int min_precision)
{
AVRational q;
int j;
q = st->time_base;
for (j=2; j<14; j+= 1+(j>2))
while (q.den / q.num < min_precision && q.num % j == 0)
q.num /= j;
while (q.den / q.num < min_precision && q.den < (1<<24))
q.den <<= 1;
return q;
}
enum AVChromaLocation ff_choose_chroma_location(AVFormatContext *s, AVStream *st)
{
AVCodecParameters *par = st->codecpar;
const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(par->format);
if (par->chroma_location != AVCHROMA_LOC_UNSPECIFIED)
return par->chroma_location;
if (pix_desc) {
if (pix_desc->log2_chroma_h == 0) {
return AVCHROMA_LOC_TOPLEFT;
} else if (pix_desc->log2_chroma_w == 1 && pix_desc->log2_chroma_h == 1) {
if (par->field_order == AV_FIELD_UNKNOWN || par->field_order == AV_FIELD_PROGRESSIVE) {
switch (par->codec_id) {
case AV_CODEC_ID_MJPEG:
case AV_CODEC_ID_MPEG1VIDEO: return AVCHROMA_LOC_CENTER;
}
}
if (par->field_order == AV_FIELD_UNKNOWN || par->field_order != AV_FIELD_PROGRESSIVE) {
switch (par->codec_id) {
case AV_CODEC_ID_MPEG2VIDEO: return AVCHROMA_LOC_LEFT;
}
}
}
}
return AVCHROMA_LOC_UNSPECIFIED;
}
int avformat_alloc_output_context2(AVFormatContext **avctx, AVOutputFormat *oformat,
const char *format, const char *filename)
{
AVFormatContext *s = avformat_alloc_context();
int ret = 0;
*avctx = NULL;
if (!s)
goto nomem;
if (!oformat) {
if (format) {
oformat = av_guess_format(format, NULL, NULL);
if (!oformat) {
av_log(s, AV_LOG_ERROR, "Requested output format '%s' is not a suitable output format\n", format);
ret = AVERROR(EINVAL);
goto error;
}
} else {
oformat = av_guess_format(NULL, filename, NULL);
if (!oformat) {
ret = AVERROR(EINVAL);
av_log(s, AV_LOG_ERROR, "Unable to find a suitable output format for '%s'\n",
filename);
goto error;
}
}
}
s->oformat = oformat;
if (s->oformat->priv_data_size > 0) {
s->priv_data = av_mallocz(s->oformat->priv_data_size);
if (!s->priv_data)
goto nomem;
if (s->oformat->priv_class) {
*(const AVClass**)s->priv_data= s->oformat->priv_class;
av_opt_set_defaults(s->priv_data);
}
} else
s->priv_data = NULL;
if (filename)
av_strlcpy(s->filename, filename, sizeof(s->filename));
*avctx = s;
return 0;
nomem:
av_log(s, AV_LOG_ERROR, "Out of memory\n");
ret = AVERROR(ENOMEM);
error:
avformat_free_context(s);
return ret;
}
static int validate_codec_tag(AVFormatContext *s, AVStream *st)
{
const AVCodecTag *avctag;
int n;
enum AVCodecID id = AV_CODEC_ID_NONE;
int64_t tag = -1;
/**
* 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->codecpar->codec_tag)) {
id = avctag->id;
if (id == st->codecpar->codec_id)
return 1;
}
if (avctag->id == st->codecpar->codec_id)
tag = avctag->tag;
avctag++;
}
}
if (id != AV_CODEC_ID_NONE)
return 0;
if (tag >= 0 && (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;
AVCodecParameters *par = NULL;
AVOutputFormat *of = s->oformat;
const AVCodecDescriptor *desc;
AVDictionaryEntry *e;
if (options)
av_dict_copy(&tmp, *options, 0);
if ((ret = av_opt_set_dict(s, &tmp)) < 0)
goto fail;
if (s->priv_data && s->oformat->priv_class && *(const AVClass**)s->priv_data==s->oformat->priv_class &&
(ret = av_opt_set_dict2(s->priv_data, &tmp, AV_OPT_SEARCH_CHILDREN)) < 0)
goto fail;
#if FF_API_LAVF_AVCTX
FF_DISABLE_DEPRECATION_WARNINGS
if (s->nb_streams && s->streams[0]->codec->flags & AV_CODEC_FLAG_BITEXACT) {
if (!(s->flags & AVFMT_FLAG_BITEXACT)) {
#if FF_API_LAVF_BITEXACT
av_log(s, AV_LOG_WARNING,
"Setting the AVFormatContext to bitexact mode, because "
"the AVCodecContext is in that mode. This behavior will "
"change in the future. To keep the current behavior, set "
"AVFormatContext.flags |= AVFMT_FLAG_BITEXACT.\n");
s->flags |= AVFMT_FLAG_BITEXACT;
#else
av_log(s, AV_LOG_WARNING,
"The AVFormatContext is not in set to bitexact mode, only "
"the AVCodecContext. If this is not intended, set "
"AVFormatContext.flags |= AVFMT_FLAG_BITEXACT.\n");
#endif
}
}
FF_ENABLE_DEPRECATION_WARNINGS
#endif
// some sanity checks
if (s->nb_streams == 0 && !(of->flags & AVFMT_NOSTREAMS)) {
av_log(s, AV_LOG_ERROR, "No streams to mux were specified\n");
ret = AVERROR(EINVAL);
goto fail;
}
for (i = 0; i < s->nb_streams; i++) {
st = s->streams[i];
par = st->codecpar;
#if FF_API_LAVF_CODEC_TB && FF_API_LAVF_AVCTX
FF_DISABLE_DEPRECATION_WARNINGS
if (!st->time_base.num && st->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, st->codec->time_base.num, st->codec->time_base.den);
}
FF_ENABLE_DEPRECATION_WARNINGS
#endif
#if FF_API_LAVF_AVCTX
FF_DISABLE_DEPRECATION_WARNINGS
if (st->codecpar->codec_type == AVMEDIA_TYPE_UNKNOWN &&
st->codec->codec_type != AVMEDIA_TYPE_UNKNOWN) {
av_log(s, AV_LOG_WARNING, "Using AVStream.codec to pass codec "
"parameters to muxers is deprecated, use AVStream.codecpar "
"instead.\n");
ret = avcodec_parameters_from_context(st->codecpar, st->codec);
if (ret < 0)
goto fail;
}
FF_ENABLE_DEPRECATION_WARNINGS
#endif
/* update internal context from codecpar, old bsf api needs this
* FIXME: remove when autobsf uses new bsf API */
ret = avcodec_parameters_to_context(st->internal->avctx, st->codecpar);
if (ret < 0)
goto fail;
if (!st->time_base.num) {
/* fall back on the default timebase values */
if (par->codec_type == AVMEDIA_TYPE_AUDIO && par->sample_rate)
avpriv_set_pts_info(st, 64, 1, par->sample_rate);
else
avpriv_set_pts_info(st, 33, 1, 90000);
}
switch (par->codec_type) {
case AVMEDIA_TYPE_AUDIO:
if (par->sample_rate <= 0) {
av_log(s, AV_LOG_ERROR, "sample rate not set\n");
ret = AVERROR(EINVAL);
goto fail;
}
if (!par->block_align)
par->block_align = par->channels *
av_get_bits_per_sample(par->codec_id) >> 3;
break;
case AVMEDIA_TYPE_VIDEO:
if ((par->width <= 0 || par->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, par->sample_aspect_ratio)
&& fabs(av_q2d(st->sample_aspect_ratio) - av_q2d(par->sample_aspect_ratio)) > 0.004*av_q2d(st->sample_aspect_ratio)
) {
if (st->sample_aspect_ratio.num != 0 &&
st->sample_aspect_ratio.den != 0 &&
par->sample_aspect_ratio.num != 0 &&
par->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,
par->sample_aspect_ratio.num,
par->sample_aspect_ratio.den);
ret = AVERROR(EINVAL);
goto fail;
}
}
break;
}
desc = avcodec_descriptor_get(par->codec_id);
if (desc && desc->props & AV_CODEC_PROP_REORDER)
st->internal->reorder = 1;
if (of->codec_tag) {
if ( par->codec_tag
&& par->codec_id == AV_CODEC_ID_RAWVIDEO
&& ( av_codec_get_tag(of->codec_tag, par->codec_id) == 0
|| av_codec_get_tag(of->codec_tag, par->codec_id) == MKTAG('r', 'a', 'w', ' '))
&& !validate_codec_tag(s, st)) {
// the current rawvideo encoding system ends up setting
// the wrong codec_tag for avi/mov, we override it here
par->codec_tag = 0;
}
if (par->codec_tag) {
if (!validate_codec_tag(s, st)) {
char tagbuf[32], tagbuf2[32];
av_get_codec_tag_string(tagbuf, sizeof(tagbuf), par->codec_tag);
av_get_codec_tag_string(tagbuf2, sizeof(tagbuf2), av_codec_get_tag(s->oformat->codec_tag, par->codec_id));
av_log(s, AV_LOG_ERROR,
"Tag %s/0x%08x incompatible with output codec id '%d' (%s)\n",
tagbuf, par->codec_tag, par->codec_id, tagbuf2);
ret = AVERROR_INVALIDDATA;
goto fail;
}
} else
par->codec_tag = av_codec_get_tag(of->codec_tag, par->codec_id);
}
if (par->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_dict2(s->priv_data, &tmp, AV_OPT_SEARCH_CHILDREN)) < 0)
goto fail;
}
}
/* set muxer identification string */
if (!(s->flags & AVFMT_FLAG_BITEXACT)) {
av_dict_set(&s->metadata, "encoder", LIBAVFORMAT_IDENT, 0);
} else {
av_dict_set(&s->metadata, "encoder", NULL, 0);
}
for (e = NULL; e = av_dict_get(s->metadata, "encoder-", e, AV_DICT_IGNORE_SUFFIX); ) {
av_dict_set(&s->metadata, e->key, NULL, 0);
}
if (options) {
av_dict_free(options);
*options = tmp;
}
if (s->oformat->init && (ret = s->oformat->init(s)) < 0) {
if (s->oformat->deinit)
s->oformat->deinit(s);
goto fail;
}
return 0;
fail:
av_dict_free(&tmp);
return ret;
}
static int init_pts(AVFormatContext *s)
{
int i;
AVStream *st;
/* init PTS generation */
for (i = 0; i < s->nb_streams; i++) {
int64_t den = AV_NOPTS_VALUE;
st = s->streams[i];
switch (st->codecpar->codec_type) {
case AVMEDIA_TYPE_AUDIO:
den = (int64_t)st->time_base.num * st->codecpar->sample_rate;
break;
case AVMEDIA_TYPE_VIDEO:
den = (int64_t)st->time_base.num * st->time_base.den;
break;
default:
break;
}
if (!st->priv_pts)
st->priv_pts = av_mallocz(sizeof(*st->priv_pts));
if (!st->priv_pts)
return AVERROR(ENOMEM);
if (den != AV_NOPTS_VALUE) {
if (den <= 0)
return AVERROR_INVALIDDATA;
frac_init(st->priv_pts, 0, 0, den);
}
}
return 0;
}
static int write_header_internal(AVFormatContext *s)
{
if (!(s->oformat->flags & AVFMT_NOFILE) && s->pb)
avio_write_marker(s->pb, AV_NOPTS_VALUE, AVIO_DATA_MARKER_HEADER);
if (s->oformat->write_header) {
int ret = s->oformat->write_header(s);
if (ret >= 0 && s->pb && s->pb->error < 0)
ret = s->pb->error;
s->internal->write_header_ret = ret;
if (ret < 0)
return ret;
if (s->flush_packets && s->pb && s->pb->error >= 0 && s->flags & AVFMT_FLAG_FLUSH_PACKETS)
avio_flush(s->pb);
}
s->internal->header_written = 1;
if (!(s->oformat->flags & AVFMT_NOFILE) && s->pb)
avio_write_marker(s->pb, AV_NOPTS_VALUE, AVIO_DATA_MARKER_UNKNOWN);
return 0;
}
int avformat_write_header(AVFormatContext *s, AVDictionary **options)
{
int ret = 0;
if ((ret = init_muxer(s, options)) < 0)
return ret;
if (!(s->oformat->check_bitstream && s->flags & AVFMT_FLAG_AUTO_BSF)) {
ret = write_header_internal(s);
if (ret < 0)
goto fail;
}
if ((ret = init_pts(s)) < 0)
goto fail;
if (s->avoid_negative_ts < 0) {
av_assert2(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;
fail:
if (s->oformat->deinit)
s->oformat->deinit(s);
return ret;
}
#define AV_PKT_FLAG_UNCODED_FRAME 0x2000
/* Note: using sizeof(AVFrame) from outside lavu is unsafe in general, but
it is only being used internally to this file as a consistency check.
The value is chosen to be very unlikely to appear on its own and to cause
immediate failure if used anywhere as a real size. */
#define UNCODED_FRAME_PACKET_SIZE (INT_MIN / 3 * 2 + (int)sizeof(AVFrame))
#if FF_API_COMPUTE_PKT_FIELDS2 && FF_API_LAVF_AVCTX
FF_DISABLE_DEPRECATION_WARNINGS
//FIXME merge with compute_pkt_fields
static int compute_muxer_pkt_fields(AVFormatContext *s, AVStream *st, AVPacket *pkt)
{
int delay = FFMAX(st->codecpar->video_delay, st->internal->avctx->max_b_frames > 0);
int num, den, i;
int frame_size;
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;
}
if (s->debug & FF_FDEBUG_TS)
av_log(s, AV_LOG_TRACE, "compute_muxer_pkt_fields: pts:%s dts:%s cur_dts:%s b:%d size:%d st:%d\n",
av_ts2str(pkt->pts), av_ts2str(pkt->dts), av_ts2str(st->cur_dts), delay, pkt->size, pkt->stream_index);
if (pkt->duration < 0 && st->codecpar->codec_type != AVMEDIA_TYPE_SUBTITLE) {
av_log(s, AV_LOG_WARNING, "Packet with invalid duration %"PRId64" in stream %d\n",
pkt->duration, pkt->stream_index);
pkt->duration = 0;
}
/* 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;
//XXX/FIXME this is a temporary hack until all encoders output pts
if ((pkt->pts == 0 || pkt->pts == AV_NOPTS_VALUE) && pkt->dts == AV_NOPTS_VALUE && !delay) {
static int warned;
if (!warned) {
av_log(s, AV_LOG_WARNING, "Encoder did not produce proper pts, making some up.\n");
warned = 1;
}
pkt->dts =
// pkt->pts= st->cur_dts;
pkt->pts = st->priv_pts->val;
}
//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->codecpar->codec_type != AVMEDIA_TYPE_SUBTITLE &&
st->codecpar->codec_type != AVMEDIA_TYPE_DATA &&
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: %s >= %s\n",
st->index, av_ts2str(st->cur_dts), av_ts2str(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 (%s) < dts (%s) in stream %d\n",
av_ts2str(pkt->pts), av_ts2str(pkt->dts),
st->index);
return AVERROR(EINVAL);
}
if (s->debug & FF_FDEBUG_TS)
av_log(s, AV_LOG_TRACE, "av_write_frame: pts2:%s dts2:%s\n",
av_ts2str(pkt->pts), av_ts2str(pkt->dts));
st->cur_dts = pkt->dts;
st->priv_pts->val = pkt->dts;
/* update pts */
switch (st->codecpar->codec_type) {
case AVMEDIA_TYPE_AUDIO:
frame_size = (pkt->flags & AV_PKT_FLAG_UNCODED_FRAME) ?
((AVFrame *)pkt->data)->nb_samples :
av_get_audio_frame_duration(st->codec, pkt->size);
/* HACK/FIXME, we skip the initial 0 size packets as they are most
* likely equal to the encoder delay, but it would be better if we
* had the real timestamps from the encoder */
if (frame_size >= 0 && (pkt->size || st->priv_pts->num != st->priv_pts->den >> 1 || st->priv_pts->val)) {
frac_add(st->priv_pts, (int64_t)st->time_base.den * frame_size);
}
break;
case AVMEDIA_TYPE_VIDEO:
frac_add(st->priv_pts, (int64_t)st->time_base.den * st->time_base.num);
break;
}
return 0;
}
FF_ENABLE_DEPRECATION_WARNINGS
#endif
/**
* Make timestamps non negative, move side data from payload to internal struct, call muxer, and restore
* sidedata.
*
* 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, did_split;
int64_t pts_backup, dts_backup;
pts_backup = pkt->pts;
dts_backup = pkt->dts;
if (s->output_ts_offset) {
AVStream *st = s->streams[pkt->stream_index];
int64_t offset = av_rescale_q(s->output_ts_offset, AV_TIME_BASE_Q, st->time_base);
if (pkt->dts != AV_NOPTS_VALUE)
pkt->dts += offset;
if (pkt->pts != AV_NOPTS_VALUE)
pkt->pts += offset;
}
if (s->avoid_negative_ts > 0) {
AVStream *st = s->streams[pkt->stream_index];
int64_t offset = st->mux_ts_offset;
int64_t ts = s->internal->avoid_negative_ts_use_pts ? pkt->pts : pkt->dts;
if (s->internal->offset == AV_NOPTS_VALUE && ts != AV_NOPTS_VALUE &&
(ts < 0 || s->avoid_negative_ts == AVFMT_AVOID_NEG_TS_MAKE_ZERO)) {
s->internal->offset = -ts;
s->internal->offset_timebase = st->time_base;
}
if (s->internal->offset != AV_NOPTS_VALUE && !offset) {
offset = st->mux_ts_offset =
av_rescale_q_rnd(s->internal->offset,
s->internal->offset_timebase,
st->time_base,
AV_ROUND_UP);
}
if (pkt->dts != AV_NOPTS_VALUE)
pkt->dts += offset;
if (pkt->pts != AV_NOPTS_VALUE)
pkt->pts += offset;
if (s->internal->avoid_negative_ts_use_pts) {
if (pkt->pts != AV_NOPTS_VALUE && pkt->pts < 0) {
av_log(s, AV_LOG_WARNING, "failed to avoid negative "
"pts %s in stream %d.\n"
"Try -avoid_negative_ts 1 as a possible workaround.\n",
av_ts2str(pkt->dts),
pkt->stream_index
);
}
} else {
av_assert2(pkt->dts == AV_NOPTS_VALUE || pkt->dts >= 0 || s->max_interleave_delta > 0);
if (pkt->dts != AV_NOPTS_VALUE && pkt->dts < 0) {
av_log(s, AV_LOG_WARNING,
"Packets poorly interleaved, failed to avoid negative "
"timestamp %s in stream %d.\n"
"Try -max_interleave_delta 0 as a possible workaround.\n",
av_ts2str(pkt->dts),
pkt->stream_index
);
}
}
}
did_split = av_packet_split_side_data(pkt);
if (!s->internal->header_written) {
ret = s->internal->write_header_ret ? s->internal->write_header_ret : write_header_internal(s);
if (ret < 0)
goto fail;
}
if ((pkt->flags & AV_PKT_FLAG_UNCODED_FRAME)) {
AVFrame *frame = (AVFrame *)pkt->data;
av_assert0(pkt->size == UNCODED_FRAME_PACKET_SIZE);
ret = s->oformat->write_uncoded_frame(s, pkt->stream_index, &frame, 0);
av_frame_free(&frame);
} else {
ret = s->oformat->write_packet(s, pkt);
}
if (s->pb && ret >= 0) {
if (s->flush_packets && s->flags & AVFMT_FLAG_FLUSH_PACKETS)
avio_flush(s->pb);
if (s->pb->error < 0)
ret = s->pb->error;
}
fail:
if (did_split)
av_packet_merge_side_data(pkt);
if (ret < 0) {
pkt->pts = pts_backup;
pkt->dts = dts_backup;
}
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]->codecpar->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 && FF_API_LAVF_AVCTX
/* 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;
}
static int do_packet_auto_bsf(AVFormatContext *s, AVPacket *pkt) {
AVStream *st = s->streams[pkt->stream_index];
int i, ret;
if (!(s->flags & AVFMT_FLAG_AUTO_BSF))
return 1;
if (s->oformat->check_bitstream) {
if (!st->internal->bitstream_checked) {
if ((ret = s->oformat->check_bitstream(s, pkt)) < 0)
return ret;
else if (ret == 1)
st->internal->bitstream_checked = 1;
}
}
for (i = 0; i < st->internal->nb_bsfcs; i++) {
AVBSFContext *ctx = st->internal->bsfcs[i];
if (i > 0) {
AVBSFContext* prev_ctx = st->internal->bsfcs[i - 1];
if (prev_ctx->par_out->extradata_size != ctx->par_in->extradata_size) {
if ((ret = avcodec_parameters_copy(ctx->par_in, prev_ctx->par_out)) < 0)
return ret;
}
}
// TODO: when any bitstream filter requires flushing at EOF, we'll need to
// flush each stream's BSF chain on write_trailer.
if ((ret = av_bsf_send_packet(ctx, pkt)) < 0) {
av_log(ctx, AV_LOG_ERROR,
"Failed to send packet to filter %s for stream %d",
ctx->filter->name, pkt->stream_index);
return ret;
}
// TODO: when any automatically-added bitstream filter is generating multiple
// output packets for a single input one, we'll need to call this in a loop
// and write each output packet.
if ((ret = av_bsf_receive_packet(ctx, pkt)) < 0) {
if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
return 0;
av_log(ctx, AV_LOG_ERROR,
"Failed to send packet to filter %s for stream %d",
ctx->filter->name, pkt->stream_index);
return ret;
}
if (i == st->internal->nb_bsfcs - 1) {
if (ctx->par_out->extradata_size != st->codecpar->extradata_size) {
if ((ret = avcodec_parameters_copy(st->codecpar, ctx->par_out)) < 0)
return ret;
}
}
}
return 1;
}
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) {
if (!s->internal->header_written) {
ret = s->internal->write_header_ret ? s->internal->write_header_ret : write_header_internal(s);
if (ret < 0)
return ret;
}
ret = s->oformat->write_packet(s, NULL);
if (s->flush_packets && s->pb && s->pb->error >= 0 && s->flags & AVFMT_FLAG_FLUSH_PACKETS)
avio_flush(s->pb);
if (ret >= 0 && s->pb && s->pb->error < 0)
ret = s->pb->error;
return ret;
}
return 1;
}
ret = do_packet_auto_bsf(s, pkt);
if (ret <= 0)
return ret;
#if FF_API_COMPUTE_PKT_FIELDS2 && FF_API_LAVF_AVCTX
ret = compute_muxer_pkt_fields(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->pb && s->pb->error < 0)
ret = s->pb->error;
if (ret >= 0)
s->streams[pkt->stream_index]->nb_frames++;
return ret;
}
#define CHUNK_START 0x1000
int ff_interleave_add_packet(AVFormatContext *s, AVPacket *pkt,
int (*compare)(AVFormatContext *, AVPacket *, AVPacket *))
{
int ret;
AVPacketList **next_point, *this_pktl;
AVStream *st = s->streams[pkt->stream_index];
int chunked = s->max_chunk_size || s->max_chunk_duration;
this_pktl = av_mallocz(sizeof(AVPacketList));
if (!this_pktl)
return AVERROR(ENOMEM);
if ((pkt->flags & AV_PKT_FLAG_UNCODED_FRAME)) {
av_assert0(pkt->size == UNCODED_FRAME_PACKET_SIZE);
av_assert0(((AVFrame *)pkt->data)->buf);
this_pktl->pkt = *pkt;
pkt->buf = NULL;
pkt->side_data = NULL;
pkt->side_data_elems = 0;
} else {
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 = &(st->last_in_packet_buffer->next);
} else {
next_point = &s->internal->packet_buffer;
}
if (chunked) {
uint64_t max= av_rescale_q_rnd(s->max_chunk_duration, AV_TIME_BASE_Q, st->time_base, AV_ROUND_UP);
st->interleaver_chunk_size += pkt->size;
st->interleaver_chunk_duration += pkt->duration;
if ( (s->max_chunk_size && st->interleaver_chunk_size > s->max_chunk_size)
|| (max && st->interleaver_chunk_duration > max)) {
st->interleaver_chunk_size = 0;
this_pktl->pkt.flags |= CHUNK_START;
if (max && st->interleaver_chunk_duration > max) {
int64_t syncoffset = (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)*max/2;
int64_t syncto = av_rescale(pkt->dts + syncoffset, 1, max)*max - syncoffset;
st->interleaver_chunk_duration += (pkt->dts - syncto)/8 - max;
} else
st->interleaver_chunk_duration = 0;
}
}
if (*next_point) {
if (chunked && !(this_pktl->pkt.flags & CHUNK_START))
goto next_non_null;
if (compare(s, &s->internal->packet_buffer_end->pkt, pkt)) {
while ( *next_point
&& ((chunked && !((*next_point)->pkt.flags&CHUNK_START))
|| !compare(s, &(*next_point)->pkt, pkt)))
next_point = &(*next_point)->next;
if (*next_point)
goto next_non_null;
} else {
next_point = &(s->internal->packet_buffer_end->next);
}
}
av_assert1(!*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 (s->audio_preload && ((st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) != (st2->codecpar->codec_type == AVMEDIA_TYPE_AUDIO))) {
int64_t ts = av_rescale_q(pkt ->dts, st ->time_base, AV_TIME_BASE_Q) - s->audio_preload*(st ->codecpar->codec_type == AVMEDIA_TYPE_AUDIO);
int64_t ts2= av_rescale_q(next->dts, st2->time_base, AV_TIME_BASE_Q) - s->audio_preload*(st2->codecpar->codec_type == AVMEDIA_TYPE_AUDIO);
if (ts == ts2) {
ts= ( pkt ->dts* st->time_base.num*AV_TIME_BASE - s->audio_preload*(int64_t)(st ->codecpar->codec_type == AVMEDIA_TYPE_AUDIO)* st->time_base.den)*st2->time_base.den
-( next->dts*st2->time_base.num*AV_TIME_BASE - s->audio_preload*(int64_t)(st2->codecpar->codec_type == AVMEDIA_TYPE_AUDIO)*st2->time_base.den)* st->time_base.den;
ts2=0;
}
comp= (ts>ts2) - (ts<ts2);
}
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 noninterleaved_count = 0;
int i, ret;
int eof = flush;
if (pkt) {
if ((ret = ff_interleave_add_packet(s, pkt, interleave_compare_dts)) < 0)
return ret;
}
for (i = 0; i < s->nb_streams; i++) {
if (s->streams[i]->last_in_packet_buffer) {
++stream_count;
} else if (s->streams[i]->codecpar->codec_type != AVMEDIA_TYPE_ATTACHMENT &&
s->streams[i]->codecpar->codec_id != AV_CODEC_ID_VP8 &&
s->streams[i]->codecpar->codec_id != AV_CODEC_ID_VP9) {
++noninterleaved_count;
}
}
if (s->internal->nb_interleaved_streams == stream_count)
flush = 1;
if (s->max_interleave_delta > 0 &&
s->internal->packet_buffer &&
!flush &&
s->internal->nb_interleaved_streams == stream_count+noninterleaved_count
) {
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);
}
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;
}
}
if (s->internal->packet_buffer &&
eof &&
(s->flags & AVFMT_FLAG_SHORTEST) &&
s->internal->shortest_end == AV_NOPTS_VALUE) {
AVPacket *top_pkt = &s->internal->packet_buffer->pkt;
s->internal->shortest_end = av_rescale_q(top_pkt->dts,
s->streams[top_pkt->stream_index]->time_base,
AV_TIME_BASE_Q);
}
if (s->internal->shortest_end != AV_NOPTS_VALUE) {
while (s->internal->packet_buffer) {
AVPacket *top_pkt = &s->internal->packet_buffer->pkt;
AVStream *st;
int64_t top_dts = av_rescale_q(top_pkt->dts,
s->streams[top_pkt->stream_index]->time_base,
AV_TIME_BASE_Q);
if (s->internal->shortest_end + 1 >= top_dts)
break;
pktl = s->internal->packet_buffer;
st = s->streams[pktl->pkt.stream_index];
s->internal->packet_buffer = pktl->next;
if (!s->internal->packet_buffer)
s->internal->packet_buffer_end = NULL;
if (st->last_in_packet_buffer == pktl)
st->last_in_packet_buffer = NULL;
av_packet_unref(&pktl->pkt);
av_freep(&pktl);
flush = 0;
}
}
if (stream_count && flush) {
AVStream *st;
pktl = s->internal->packet_buffer;
*out = pktl->pkt;
st = s->streams[out->stream_index];
s->internal->packet_buffer = pktl->next;
if (!s->internal->packet_buffer)
s->internal->packet_buffer_end = NULL;
if (st->last_in_packet_buffer == pktl)
st->last_in_packet_buffer = NULL;
av_freep(&pktl);
return 1;
} else {
av_init_packet(out);
return 0;
}
}
const AVPacket *ff_interleaved_peek(AVFormatContext *s, int stream, int64_t *ts_offset)
{
AVPacketList *pktl = s->internal->packet_buffer;
while (pktl) {
if (pktl->pkt.stream_index == stream) {
AVPacket *pkt = &pktl->pkt;
AVStream *st = s->streams[pkt->stream_index];
*ts_offset = st->mux_ts_offset;
if (s->output_ts_offset)
*ts_offset += av_rescale_q(s->output_ts_offset, AV_TIME_BASE_Q, st->time_base);
return pkt;
}
pktl = pktl->next;
}
return NULL;
}
/**
* 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];
ret = do_packet_auto_bsf(s, pkt);
if (ret == 0)
return 0;
else if (ret < 0)
goto fail;
if (s->debug & FF_FDEBUG_TS)
av_log(s, AV_LOG_TRACE, "av_interleaved_write_frame size:%d dts:%s pts:%s\n",
pkt->size, av_ts2str(pkt->dts), av_ts2str(pkt->pts));
#if FF_API_COMPUTE_PKT_FIELDS2 && FF_API_LAVF_AVCTX
if ((ret = compute_muxer_pkt_fields(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;
if(s->pb && s->pb->error)
return s->pb->error;
}
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)
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->pb && s->pb->error)
goto fail;
}
if (!s->internal->header_written) {
ret = s->internal->write_header_ret ? s->internal->write_header_ret : write_header_internal(s);
if (ret < 0)
goto fail;
}
fail:
if (s->internal->header_written && s->oformat->write_trailer) {
if (!(s->oformat->flags & AVFMT_NOFILE) && s->pb)
avio_write_marker(s->pb, AV_NOPTS_VALUE, AVIO_DATA_MARKER_TRAILER);
if (ret >= 0) {
ret = s->oformat->write_trailer(s);
} else {
s->oformat->write_trailer(s);
}
}
if (s->oformat->deinit)
s->oformat->deinit(s);
if (s->pb)
avio_flush(s->pb);
if (ret == 0)
ret = s->pb ? s->pb->error : 0;
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 av_get_output_timestamp(struct AVFormatContext *s, int stream,
int64_t *dts, int64_t *wall)
{
if (!s->oformat || !s->oformat->get_output_timestamp)
return AVERROR(ENOSYS);
s->oformat->get_output_timestamp(s, stream, dts, wall);
return 0;
}
int ff_write_chained(AVFormatContext *dst, int dst_stream, AVPacket *pkt,
AVFormatContext *src, int interleave)
{
AVPacket local_pkt;
int ret;
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);
if (pkt->duration)
local_pkt.duration = av_rescale_q(pkt->duration,
src->streams[pkt->stream_index]->time_base,
dst->streams[dst_stream]->time_base);
if (interleave) ret = av_interleaved_write_frame(dst, &local_pkt);
else ret = av_write_frame(dst, &local_pkt);
pkt->buf = local_pkt.buf;
pkt->side_data = local_pkt.side_data;
pkt->side_data_elems = local_pkt.side_data_elems;
return ret;
}
static int av_write_uncoded_frame_internal(AVFormatContext *s, int stream_index,
AVFrame *frame, int interleaved)
{
AVPacket pkt, *pktp;
av_assert0(s->oformat);
if (!s->oformat->write_uncoded_frame)
return AVERROR(ENOSYS);
if (!frame) {
pktp = NULL;
} else {
pktp = &pkt;
av_init_packet(&pkt);
pkt.data = (void *)frame;
pkt.size = UNCODED_FRAME_PACKET_SIZE;
pkt.pts =
pkt.dts = frame->pts;
pkt.duration = av_frame_get_pkt_duration(frame);
pkt.stream_index = stream_index;
pkt.flags |= AV_PKT_FLAG_UNCODED_FRAME;
}
return interleaved ? av_interleaved_write_frame(s, pktp) :
av_write_frame(s, pktp);
}
int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
AVFrame *frame)
{
return av_write_uncoded_frame_internal(s, stream_index, frame, 0);
}
int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index,
AVFrame *frame)
{
return av_write_uncoded_frame_internal(s, stream_index, frame, 1);
}
int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index)
{
av_assert0(s->oformat);
if (!s->oformat->write_uncoded_frame)
return AVERROR(ENOSYS);
return s->oformat->write_uncoded_frame(s, stream_index, NULL,
AV_WRITE_UNCODED_FRAME_QUERY);
}
Reference in New Issue View Git Blame Copy Permalink