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FFmpeg/libavformat/flvenc.c
Anton Khirnov 9200514ad8 lavf: replace AVStream.codec with AVStream.codecpar
Currently, AVStream contains an embedded AVCodecContext instance, which
is used by demuxers to export stream parameters to the caller and by
muxers to receive stream parameters from the caller. It is also used
internally as the codec context that is passed to parsers.

In addition, it is also widely used by the callers as the decoding (when
demuxer) or encoding (when muxing) context, though this has been
officially discouraged since Libav 11.

There are multiple important problems with this approach:
    - the fields in AVCodecContext are in general one of
        * stream parameters
        * codec options
        * codec state
      However, it's not clear which ones are which. It is consequently
      unclear which fields are a demuxer allowed to set or a muxer allowed to
      read. This leads to erratic behaviour depending on whether decoding or
      encoding is being performed or not (and whether it uses the AVStream
      embedded codec context).
    - various synchronization issues arising from the fact that the same
      context is used by several different APIs (muxers/demuxers,
      parsers, bitstream filters and encoders/decoders) simultaneously, with
      there being no clear rules for who can modify what and the different
      processes being typically delayed with respect to each other.
    - avformat_find_stream_info() making it necessary to support opening
      and closing a single codec context multiple times, thus
      complicating the semantics of freeing various allocated objects in the
      codec context.

Those problems are resolved by replacing the AVStream embedded codec
context with a newly added AVCodecParameters instance, which stores only
the stream parameters exported by the demuxers or read by the muxers.
2016-02-23 17:01:58 +01:00

592 lines
20 KiB
C

/*
* FLV muxer
* Copyright (c) 2003 The Libav Project
*
* 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 "libavutil/dict.h"
#include "libavutil/intfloat.h"
#include "avc.h"
#include "avformat.h"
#include "flv.h"
#include "internal.h"
#include "metadata.h"
#undef NDEBUG
#include <assert.h>
static const AVCodecTag flv_video_codec_ids[] = {
{ AV_CODEC_ID_FLV1, FLV_CODECID_H263 },
{ AV_CODEC_ID_FLASHSV, FLV_CODECID_SCREEN },
{ AV_CODEC_ID_FLASHSV2, FLV_CODECID_SCREEN2 },
{ AV_CODEC_ID_VP6F, FLV_CODECID_VP6 },
{ AV_CODEC_ID_VP6A, FLV_CODECID_VP6A },
{ AV_CODEC_ID_H264, FLV_CODECID_H264 },
{ AV_CODEC_ID_NONE, 0 }
};
static const AVCodecTag flv_audio_codec_ids[] = {
{ AV_CODEC_ID_MP3, FLV_CODECID_MP3 >> FLV_AUDIO_CODECID_OFFSET },
{ AV_CODEC_ID_PCM_U8, FLV_CODECID_PCM >> FLV_AUDIO_CODECID_OFFSET },
{ AV_CODEC_ID_PCM_S16BE, FLV_CODECID_PCM >> FLV_AUDIO_CODECID_OFFSET },
{ AV_CODEC_ID_PCM_S16LE, FLV_CODECID_PCM_LE >> FLV_AUDIO_CODECID_OFFSET },
{ AV_CODEC_ID_ADPCM_SWF, FLV_CODECID_ADPCM >> FLV_AUDIO_CODECID_OFFSET },
{ AV_CODEC_ID_AAC, FLV_CODECID_AAC >> FLV_AUDIO_CODECID_OFFSET },
{ AV_CODEC_ID_NELLYMOSER, FLV_CODECID_NELLYMOSER >> FLV_AUDIO_CODECID_OFFSET },
{ AV_CODEC_ID_PCM_MULAW, FLV_CODECID_PCM_MULAW >> FLV_AUDIO_CODECID_OFFSET },
{ AV_CODEC_ID_PCM_ALAW, FLV_CODECID_PCM_ALAW >> FLV_AUDIO_CODECID_OFFSET },
{ AV_CODEC_ID_SPEEX, FLV_CODECID_SPEEX >> FLV_AUDIO_CODECID_OFFSET },
{ AV_CODEC_ID_NONE, 0 }
};
typedef struct FLVContext {
int reserved;
int64_t duration_offset;
int64_t filesize_offset;
int64_t duration;
int64_t delay; ///< first dts delay (needed for AVC & Speex)
AVCodecParameters *audio_par;
AVCodecParameters *video_par;
double framerate;
AVCodecParameters *data_par;
} FLVContext;
typedef struct FLVStreamContext {
int64_t last_ts; ///< last timestamp for each stream
} FLVStreamContext;
static int get_audio_flags(AVFormatContext *s, AVCodecParameters *par)
{
int flags = (par->bits_per_coded_sample == 16) ? FLV_SAMPLESSIZE_16BIT
: FLV_SAMPLESSIZE_8BIT;
if (par->codec_id == AV_CODEC_ID_AAC) // specs force these parameters
return FLV_CODECID_AAC | FLV_SAMPLERATE_44100HZ |
FLV_SAMPLESSIZE_16BIT | FLV_STEREO;
else if (par->codec_id == AV_CODEC_ID_SPEEX) {
if (par->sample_rate != 16000) {
av_log(s, AV_LOG_ERROR,
"flv only supports wideband (16kHz) Speex audio\n");
return -1;
}
if (par->channels != 1) {
av_log(s, AV_LOG_ERROR, "flv only supports mono Speex audio\n");
return -1;
}
return FLV_CODECID_SPEEX | FLV_SAMPLERATE_11025HZ | FLV_SAMPLESSIZE_16BIT;
} else {
switch (par->sample_rate) {
case 44100:
flags |= FLV_SAMPLERATE_44100HZ;
break;
case 22050:
flags |= FLV_SAMPLERATE_22050HZ;
break;
case 11025:
flags |= FLV_SAMPLERATE_11025HZ;
break;
case 16000: // nellymoser only
case 8000: // nellymoser only
case 5512: // not MP3
if (par->codec_id != AV_CODEC_ID_MP3) {
flags |= FLV_SAMPLERATE_SPECIAL;
break;
}
default:
av_log(s, AV_LOG_ERROR,
"flv does not support that sample rate, "
"choose from (44100, 22050, 11025).\n");
return -1;
}
}
if (par->channels > 1)
flags |= FLV_STEREO;
switch (par->codec_id) {
case AV_CODEC_ID_MP3:
flags |= FLV_CODECID_MP3 | FLV_SAMPLESSIZE_16BIT;
break;
case AV_CODEC_ID_PCM_U8:
flags |= FLV_CODECID_PCM | FLV_SAMPLESSIZE_8BIT;
break;
case AV_CODEC_ID_PCM_S16BE:
flags |= FLV_CODECID_PCM | FLV_SAMPLESSIZE_16BIT;
break;
case AV_CODEC_ID_PCM_S16LE:
flags |= FLV_CODECID_PCM_LE | FLV_SAMPLESSIZE_16BIT;
break;
case AV_CODEC_ID_ADPCM_SWF:
flags |= FLV_CODECID_ADPCM | FLV_SAMPLESSIZE_16BIT;
break;
case AV_CODEC_ID_NELLYMOSER:
if (par->sample_rate == 8000)
flags |= FLV_CODECID_NELLYMOSER_8KHZ_MONO | FLV_SAMPLESSIZE_16BIT;
else if (par->sample_rate == 16000)
flags |= FLV_CODECID_NELLYMOSER_16KHZ_MONO | FLV_SAMPLESSIZE_16BIT;
else
flags |= FLV_CODECID_NELLYMOSER | FLV_SAMPLESSIZE_16BIT;
break;
case AV_CODEC_ID_PCM_MULAW:
flags = FLV_CODECID_PCM_MULAW | FLV_SAMPLERATE_SPECIAL | FLV_SAMPLESSIZE_16BIT;
break;
case AV_CODEC_ID_PCM_ALAW:
flags = FLV_CODECID_PCM_ALAW | FLV_SAMPLERATE_SPECIAL | FLV_SAMPLESSIZE_16BIT;
break;
case 0:
flags |= par->codec_tag << 4;
break;
default:
av_log(s, AV_LOG_ERROR, "codec not compatible with flv\n");
return -1;
}
return flags;
}
static void put_amf_string(AVIOContext *pb, const char *str)
{
size_t len = strlen(str);
avio_wb16(pb, len);
avio_write(pb, str, len);
}
static void put_avc_eos_tag(AVIOContext *pb, unsigned ts)
{
avio_w8(pb, FLV_TAG_TYPE_VIDEO);
avio_wb24(pb, 5); /* Tag Data Size */
avio_wb24(pb, ts); /* lower 24 bits of timestamp in ms */
avio_w8(pb, (ts >> 24) & 0x7F); /* MSB of ts in ms */
avio_wb24(pb, 0); /* StreamId = 0 */
avio_w8(pb, 23); /* ub[4] FrameType = 1, ub[4] CodecId = 7 */
avio_w8(pb, 2); /* AVC end of sequence */
avio_wb24(pb, 0); /* Always 0 for AVC EOS. */
avio_wb32(pb, 16); /* Size of FLV tag */
}
static void put_amf_double(AVIOContext *pb, double d)
{
avio_w8(pb, AMF_DATA_TYPE_NUMBER);
avio_wb64(pb, av_double2int(d));
}
static void put_amf_bool(AVIOContext *pb, int b)
{
avio_w8(pb, AMF_DATA_TYPE_BOOL);
avio_w8(pb, !!b);
}
static void write_metadata(AVFormatContext *s, unsigned int ts)
{
AVIOContext *pb = s->pb;
FLVContext *flv = s->priv_data;
int metadata_count = 0;
int64_t metadata_size_pos, data_size, metadata_count_pos;
AVDictionaryEntry *tag = NULL;
/* write meta_tag */
avio_w8(pb, 18); // tag type META
metadata_size_pos = avio_tell(pb);
avio_wb24(pb, 0); // size of data part (sum of all parts below)
avio_wb24(pb, ts); // timestamp
avio_wb32(pb, 0); // reserved
/* now data of data_size size */
/* first event name as a string */
avio_w8(pb, AMF_DATA_TYPE_STRING);
put_amf_string(pb, "onMetaData"); // 12 bytes
/* mixed array (hash) with size and string/type/data tuples */
avio_w8(pb, AMF_DATA_TYPE_MIXEDARRAY);
metadata_count_pos = avio_tell(pb);
metadata_count = 4 * !!flv->video_par +
5 * !!flv->audio_par +
1 * !!flv->data_par +
2; // +2 for duration and file size
avio_wb32(pb, metadata_count);
put_amf_string(pb, "duration");
flv->duration_offset = avio_tell(pb);
// fill in the guessed duration, it'll be corrected later if incorrect
put_amf_double(pb, s->duration / AV_TIME_BASE);
if (flv->video_par) {
put_amf_string(pb, "width");
put_amf_double(pb, flv->video_par->width);
put_amf_string(pb, "height");
put_amf_double(pb, flv->video_par->height);
put_amf_string(pb, "videodatarate");
put_amf_double(pb, flv->video_par->bit_rate / 1024.0);
if (flv->framerate != 0.0) {
put_amf_string(pb, "framerate");
put_amf_double(pb, flv->framerate);
metadata_count++;
}
put_amf_string(pb, "videocodecid");
put_amf_double(pb, flv->video_par->codec_tag);
}
if (flv->audio_par) {
put_amf_string(pb, "audiodatarate");
put_amf_double(pb, flv->audio_par->bit_rate / 1024.0);
put_amf_string(pb, "audiosamplerate");
put_amf_double(pb, flv->audio_par->sample_rate);
put_amf_string(pb, "audiosamplesize");
put_amf_double(pb, flv->audio_par->codec_id == AV_CODEC_ID_PCM_U8 ? 8 : 16);
put_amf_string(pb, "stereo");
put_amf_bool(pb, flv->audio_par->channels == 2);
put_amf_string(pb, "audiocodecid");
put_amf_double(pb, flv->audio_par->codec_tag);
}
if (flv->data_par) {
put_amf_string(pb, "datastream");
put_amf_double(pb, 0.0);
}
while ((tag = av_dict_get(s->metadata, "", tag, AV_DICT_IGNORE_SUFFIX))) {
put_amf_string(pb, tag->key);
avio_w8(pb, AMF_DATA_TYPE_STRING);
put_amf_string(pb, tag->value);
metadata_count++;
}
put_amf_string(pb, "filesize");
flv->filesize_offset = avio_tell(pb);
put_amf_double(pb, 0); // delayed write
put_amf_string(pb, "");
avio_w8(pb, AMF_END_OF_OBJECT);
/* write total size of tag */
data_size = avio_tell(pb) - metadata_size_pos - 10;
avio_seek(pb, metadata_count_pos, SEEK_SET);
avio_wb32(pb, metadata_count);
avio_seek(pb, metadata_size_pos, SEEK_SET);
avio_wb24(pb, data_size);
avio_skip(pb, data_size + 10 - 3);
avio_wb32(pb, data_size + 11);
}
static int unsupported_codec(AVFormatContext *s,
const char* type, int codec_id)
{
const AVCodecDescriptor *desc = avcodec_descriptor_get(codec_id);
av_log(s, AV_LOG_ERROR,
"%s codec %s not compatible with flv\n",
type,
desc ? desc->name : "unknown");
return AVERROR(ENOSYS);
}
static int flv_write_header(AVFormatContext *s)
{
int i;
AVIOContext *pb = s->pb;
FLVContext *flv = s->priv_data;
int64_t data_size;
for (i = 0; i < s->nb_streams; i++) {
AVCodecParameters *par = s->streams[i]->codecpar;
FLVStreamContext *sc;
switch (par->codec_type) {
case AVMEDIA_TYPE_VIDEO:
if (s->streams[i]->avg_frame_rate.den &&
s->streams[i]->avg_frame_rate.num) {
flv->framerate = av_q2d(s->streams[i]->avg_frame_rate);
}
if (flv->video_par) {
av_log(s, AV_LOG_ERROR,
"at most one video stream is supported in flv\n");
return AVERROR(EINVAL);
}
flv->video_par = par;
if (!ff_codec_get_tag(flv_video_codec_ids, par->codec_id))
return unsupported_codec(s, "Video", par->codec_id);
break;
case AVMEDIA_TYPE_AUDIO:
if (flv->audio_par) {
av_log(s, AV_LOG_ERROR,
"at most one audio stream is supported in flv\n");
return AVERROR(EINVAL);
}
flv->audio_par = par;
if (get_audio_flags(s, par) < 0)
return unsupported_codec(s, "Audio", par->codec_id);
break;
case AVMEDIA_TYPE_DATA:
if (par->codec_id != AV_CODEC_ID_TEXT)
return unsupported_codec(s, "Data", par->codec_id);
flv->data_par = par;
break;
default:
av_log(s, AV_LOG_ERROR, "codec not compatible with flv\n");
return -1;
}
avpriv_set_pts_info(s->streams[i], 32, 1, 1000); /* 32 bit pts in ms */
sc = av_mallocz(sizeof(FLVStreamContext));
if (!sc)
return AVERROR(ENOMEM);
s->streams[i]->priv_data = sc;
sc->last_ts = -1;
}
flv->delay = AV_NOPTS_VALUE;
avio_write(pb, "FLV", 3);
avio_w8(pb, 1);
avio_w8(pb, FLV_HEADER_FLAG_HASAUDIO * !!flv->audio_par +
FLV_HEADER_FLAG_HASVIDEO * !!flv->video_par);
avio_wb32(pb, 9);
avio_wb32(pb, 0);
for (i = 0; i < s->nb_streams; i++)
if (s->streams[i]->codecpar->codec_tag == 5) {
avio_w8(pb, 8); // message type
avio_wb24(pb, 0); // include flags
avio_wb24(pb, 0); // time stamp
avio_wb32(pb, 0); // reserved
avio_wb32(pb, 11); // size
flv->reserved = 5;
}
write_metadata(s, 0);
for (i = 0; i < s->nb_streams; i++) {
AVCodecParameters *par = s->streams[i]->codecpar;
if (par->codec_id == AV_CODEC_ID_AAC || par->codec_id == AV_CODEC_ID_H264) {
int64_t pos;
avio_w8(pb, par->codec_type == AVMEDIA_TYPE_VIDEO ?
FLV_TAG_TYPE_VIDEO : FLV_TAG_TYPE_AUDIO);
avio_wb24(pb, 0); // size patched later
avio_wb24(pb, 0); // ts
avio_w8(pb, 0); // ts ext
avio_wb24(pb, 0); // streamid
pos = avio_tell(pb);
if (par->codec_id == AV_CODEC_ID_AAC) {
avio_w8(pb, get_audio_flags(s, par));
avio_w8(pb, 0); // AAC sequence header
avio_write(pb, par->extradata, par->extradata_size);
} else {
avio_w8(pb, par->codec_tag | FLV_FRAME_KEY); // flags
avio_w8(pb, 0); // AVC sequence header
avio_wb24(pb, 0); // composition time
ff_isom_write_avcc(pb, par->extradata, par->extradata_size);
}
data_size = avio_tell(pb) - pos;
avio_seek(pb, -data_size - 10, SEEK_CUR);
avio_wb24(pb, data_size);
avio_skip(pb, data_size + 10 - 3);
avio_wb32(pb, data_size + 11); // previous tag size
}
}
return 0;
}
static int flv_write_trailer(AVFormatContext *s)
{
int64_t file_size;
AVIOContext *pb = s->pb;
FLVContext *flv = s->priv_data;
int i;
/* Add EOS tag */
for (i = 0; i < s->nb_streams; i++) {
AVCodecParameters *par = s->streams[i]->codecpar;
FLVStreamContext *sc = s->streams[i]->priv_data;
if (par->codec_type == AVMEDIA_TYPE_VIDEO &&
par->codec_id == AV_CODEC_ID_H264)
put_avc_eos_tag(pb, sc->last_ts);
}
file_size = avio_tell(pb);
/* update information */
if (avio_seek(pb, flv->duration_offset, SEEK_SET) < 0)
av_log(s, AV_LOG_WARNING, "Failed to update header with correct duration.\n");
else
put_amf_double(pb, flv->duration / (double)1000);
if (avio_seek(pb, flv->filesize_offset, SEEK_SET) < 0)
av_log(s, AV_LOG_WARNING, "Failed to update header with correct filesize.\n");
else
put_amf_double(pb, file_size);
avio_seek(pb, file_size, SEEK_SET);
return 0;
}
static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
{
AVIOContext *pb = s->pb;
AVCodecParameters *par = s->streams[pkt->stream_index]->codecpar;
FLVContext *flv = s->priv_data;
FLVStreamContext *sc = s->streams[pkt->stream_index]->priv_data;
unsigned ts;
int size = pkt->size;
uint8_t *data = NULL;
int flags = 0, flags_size;
if (par->codec_id == AV_CODEC_ID_VP6F || par->codec_id == AV_CODEC_ID_VP6A ||
par->codec_id == AV_CODEC_ID_AAC)
flags_size = 2;
else if (par->codec_id == AV_CODEC_ID_H264)
flags_size = 5;
else
flags_size = 1;
if (flv->delay == AV_NOPTS_VALUE)
flv->delay = -pkt->dts;
if (pkt->dts < -flv->delay) {
av_log(s, AV_LOG_WARNING,
"Packets are not in the proper order with respect to DTS\n");
return AVERROR(EINVAL);
}
ts = pkt->dts + flv->delay; // add delay to force positive dts
if (s->event_flags & AVSTREAM_EVENT_FLAG_METADATA_UPDATED) {
write_metadata(s, ts);
s->event_flags &= ~AVSTREAM_EVENT_FLAG_METADATA_UPDATED;
}
switch (par->codec_type) {
case AVMEDIA_TYPE_VIDEO:
avio_w8(pb, FLV_TAG_TYPE_VIDEO);
flags = ff_codec_get_tag(flv_video_codec_ids, par->codec_id);
flags |= pkt->flags & AV_PKT_FLAG_KEY ? FLV_FRAME_KEY : FLV_FRAME_INTER;
break;
case AVMEDIA_TYPE_AUDIO:
flags = get_audio_flags(s, par);
assert(size);
avio_w8(pb, FLV_TAG_TYPE_AUDIO);
break;
case AVMEDIA_TYPE_DATA:
avio_w8(pb, FLV_TAG_TYPE_META);
break;
default:
return AVERROR(EINVAL);
}
if (par->codec_id == AV_CODEC_ID_H264)
/* check if extradata looks like MP4 */
if (par->extradata_size > 0 && *(uint8_t*)par->extradata != 1)
if (ff_avc_parse_nal_units_buf(pkt->data, &data, &size) < 0)
return -1;
/* check Speex packet duration */
if (par->codec_id == AV_CODEC_ID_SPEEX && ts - sc->last_ts > 160)
av_log(s, AV_LOG_WARNING, "Warning: Speex stream has more than "
"8 frames per packet. Adobe Flash "
"Player cannot handle this!\n");
if (sc->last_ts < ts)
sc->last_ts = ts;
avio_wb24(pb, size + flags_size);
avio_wb24(pb, ts);
avio_w8(pb, (ts >> 24) & 0x7F); // timestamps are 32 bits _signed_
avio_wb24(pb, flv->reserved);
if (par->codec_type == AVMEDIA_TYPE_DATA) {
int data_size;
int64_t metadata_size_pos = avio_tell(pb);
avio_w8(pb, AMF_DATA_TYPE_STRING);
put_amf_string(pb, "onTextData");
avio_w8(pb, AMF_DATA_TYPE_MIXEDARRAY);
avio_wb32(pb, 2);
put_amf_string(pb, "type");
avio_w8(pb, AMF_DATA_TYPE_STRING);
put_amf_string(pb, "Text");
put_amf_string(pb, "text");
avio_w8(pb, AMF_DATA_TYPE_STRING);
put_amf_string(pb, pkt->data);
put_amf_string(pb, "");
avio_w8(pb, AMF_END_OF_OBJECT);
/* write total size of tag */
data_size = avio_tell(pb) - metadata_size_pos;
avio_seek(pb, metadata_size_pos - 10, SEEK_SET);
avio_wb24(pb, data_size);
avio_seek(pb, data_size + 10 - 3, SEEK_CUR);
avio_wb32(pb, data_size + 11);
} else {
avio_w8(pb,flags);
if (par->codec_id == AV_CODEC_ID_VP6F || par->codec_id == AV_CODEC_ID_VP6A) {
if (par->extradata_size)
avio_w8(pb, par->extradata[0]);
else
avio_w8(pb, ((FFALIGN(par->width, 16) - par->width) << 4) |
(FFALIGN(par->height, 16) - par->height));
} else if (par->codec_id == AV_CODEC_ID_AAC)
avio_w8(pb, 1); // AAC raw
else if (par->codec_id == AV_CODEC_ID_H264) {
avio_w8(pb, 1); // AVC NALU
avio_wb24(pb, pkt->pts - pkt->dts);
}
avio_write(pb, data ? data : pkt->data, size);
avio_wb32(pb, size + flags_size + 11); // previous tag size
flv->duration = FFMAX(flv->duration,
pkt->pts + flv->delay + pkt->duration);
}
av_free(data);
return pb->error;
}
AVOutputFormat ff_flv_muxer = {
.name = "flv",
.long_name = NULL_IF_CONFIG_SMALL("FLV (Flash Video)"),
.mime_type = "video/x-flv",
.extensions = "flv",
.priv_data_size = sizeof(FLVContext),
.audio_codec = CONFIG_LIBMP3LAME ? AV_CODEC_ID_MP3 : AV_CODEC_ID_ADPCM_SWF,
.video_codec = AV_CODEC_ID_FLV1,
.write_header = flv_write_header,
.write_packet = flv_write_packet,
.write_trailer = flv_write_trailer,
.codec_tag = (const AVCodecTag* const []) {
flv_video_codec_ids, flv_audio_codec_ids, 0
},
.flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS |
AVFMT_TS_NONSTRICT,
};