PeerStreamer

/*

 * FLV muxer

 * Copyright (c) 2003 The FFmpeg Project

 *

 * 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 "flv.h"

#include "internal.h"

#include "avc.h"

#include "metadata.h"

#undef NDEBUG

#include <assert.h>

static const AVCodecTag flv_video_codec_ids[] = {

    {CODEC_ID_FLV1,    FLV_CODECID_H263  },

    {CODEC_ID_FLASHSV, FLV_CODECID_SCREEN},

    {CODEC_ID_FLASHSV2, FLV_CODECID_SCREEN2},

    {CODEC_ID_VP6F,    FLV_CODECID_VP6   },

    {CODEC_ID_VP6,     FLV_CODECID_VP6   },

    {CODEC_ID_H264,    FLV_CODECID_H264  },

    {CODEC_ID_NONE,    0}

};

static const AVCodecTag flv_audio_codec_ids[] = {

    {CODEC_ID_MP3,       FLV_CODECID_MP3    >> FLV_AUDIO_CODECID_OFFSET},

    {CODEC_ID_PCM_U8,    FLV_CODECID_PCM    >> FLV_AUDIO_CODECID_OFFSET},

    {CODEC_ID_PCM_S16BE, FLV_CODECID_PCM    >> FLV_AUDIO_CODECID_OFFSET},

    {CODEC_ID_PCM_S16LE, FLV_CODECID_PCM_LE >> FLV_AUDIO_CODECID_OFFSET},

    {CODEC_ID_ADPCM_SWF, FLV_CODECID_ADPCM  >> FLV_AUDIO_CODECID_OFFSET},

    {CODEC_ID_AAC,       FLV_CODECID_AAC    >> FLV_AUDIO_CODECID_OFFSET},

    {CODEC_ID_NELLYMOSER, FLV_CODECID_NELLYMOSER >> FLV_AUDIO_CODECID_OFFSET},

    {CODEC_ID_SPEEX,     FLV_CODECID_SPEEX  >> FLV_AUDIO_CODECID_OFFSET},

    {CODEC_ID_NONE,      0}

};

typedef struct FLVContext {

    int reserved;

    int64_t duration_offset;

    int64_t filesize_offset;

    int64_t duration;

    int delay; ///< first dts delay for AVC

    int64_t last_video_ts;

} FLVContext;

static int get_audio_flags(AVCodecContext *enc){

    int flags = (enc->bits_per_coded_sample == 16) ? FLV_SAMPLESSIZE_16BIT : FLV_SAMPLESSIZE_8BIT;

    if (enc->codec_id == CODEC_ID_AAC) // specs force these parameters

        return FLV_CODECID_AAC | FLV_SAMPLERATE_44100HZ | FLV_SAMPLESSIZE_16BIT | FLV_STEREO;

    else if (enc->codec_id == CODEC_ID_SPEEX) {

        if (enc->sample_rate != 16000) {

            av_log(enc, AV_LOG_ERROR, "flv only supports wideband (16kHz) Speex audio\n");

            return -1;

        }

        if (enc->channels != 1) {

            av_log(enc, AV_LOG_ERROR, "flv only supports mono Speex audio\n");

            return -1;

        }

        if (enc->frame_size / 320 > 8) {

            av_log(enc, AV_LOG_WARNING, "Warning: Speex stream has more than "

                                        "8 frames per packet. Adobe Flash "

                                        "Player cannot handle this!\n");

        }

        return FLV_CODECID_SPEEX | FLV_SAMPLERATE_11025HZ | FLV_SAMPLESSIZE_16BIT;

    } else {

    switch (enc->sample_rate) {

        case    44100:

            flags |= FLV_SAMPLERATE_44100HZ;

            break;

        case    22050:

            flags |= FLV_SAMPLERATE_22050HZ;

            break;

        case    11025:

            flags |= FLV_SAMPLERATE_11025HZ;

            break;

        case     8000: //nellymoser only

        case     5512: //not mp3

            if(enc->codec_id != CODEC_ID_MP3){

                flags |= FLV_SAMPLERATE_SPECIAL;

                break;

            }

        default:

            av_log(enc, AV_LOG_ERROR, "flv does not support that sample rate, choose from (44100, 22050, 11025).\n");

            return -1;

    }

    }

    if (enc->channels > 1) {

        flags |= FLV_STEREO;

    }

    switch(enc->codec_id){

    case CODEC_ID_MP3:

        flags |= FLV_CODECID_MP3    | FLV_SAMPLESSIZE_16BIT;

        break;

    case CODEC_ID_PCM_U8:

        flags |= FLV_CODECID_PCM    | FLV_SAMPLESSIZE_8BIT;

        break;

    case CODEC_ID_PCM_S16BE:

        flags |= FLV_CODECID_PCM    | FLV_SAMPLESSIZE_16BIT;

        break;

    case CODEC_ID_PCM_S16LE:

        flags |= FLV_CODECID_PCM_LE | FLV_SAMPLESSIZE_16BIT;

        break;

    case CODEC_ID_ADPCM_SWF:

        flags |= FLV_CODECID_ADPCM | FLV_SAMPLESSIZE_16BIT;

        break;

    case CODEC_ID_NELLYMOSER:

        if (enc->sample_rate == 8000) {

            flags |= FLV_CODECID_NELLYMOSER_8KHZ_MONO | FLV_SAMPLESSIZE_16BIT;

        } else {

            flags |= FLV_CODECID_NELLYMOSER | FLV_SAMPLESSIZE_16BIT;

        }

        break;

    case 0:

        flags |= enc->codec_tag<<4;

        break;

    default:

        av_log(enc, 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_dbl2int(d));

}

static void put_amf_bool(AVIOContext *pb, int b) {

    avio_w8(pb, AMF_DATA_TYPE_BOOL);

    avio_w8(pb, !!b);

}

static int flv_write_header(AVFormatContext *s)

{

    AVIOContext *pb = s->pb;

    FLVContext *flv = s->priv_data;

    AVCodecContext *audio_enc = NULL, *video_enc = NULL;

    int i;

    double framerate = 0.0;

    int metadata_size_pos, data_size;

    AVMetadataTag *tag = NULL;

    for(i=0; i<s->nb_streams; i++){

        AVCodecContext *enc = s->streams[i]->codec;

        if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {

            if (s->streams[i]->r_frame_rate.den && s->streams[i]->r_frame_rate.num) {

                framerate = av_q2d(s->streams[i]->r_frame_rate);

            } else {

                framerate = 1/av_q2d(s->streams[i]->codec->time_base);

            }

            video_enc = enc;

            if(enc->codec_tag == 0) {

                av_log(enc, AV_LOG_ERROR, "video codec not compatible with flv\n");

                return -1;

            }

        } else {

            audio_enc = enc;

            if(get_audio_flags(enc)<0)

                return -1;

        }

        av_set_pts_info(s->streams[i], 32, 1, 1000); /* 32 bit pts in ms */

    }

    avio_write(pb, "FLV", 3);

    avio_w8(pb,1);

    avio_w8(pb,   FLV_HEADER_FLAG_HASAUDIO * !!audio_enc

                 + FLV_HEADER_FLAG_HASVIDEO * !!video_enc);

    avio_wb32(pb,9);

    avio_wb32(pb,0);

    for(i=0; i<s->nb_streams; i++){

        if(s->streams[i]->codec->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;

        }

    }

    flv->last_video_ts = -1;

    /* write meta_tag */

    avio_w8(pb, 18);         // tag type META

    metadata_size_pos= url_ftell(pb);

    avio_wb24(pb, 0);          // size of data part (sum of all parts below)

    avio_wb24(pb, 0);          // time stamp

    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);

    avio_wb32(pb, 5*!!video_enc + 5*!!audio_enc + 2); // +2 for duration and file size

    put_amf_string(pb, "duration");

    flv->duration_offset= url_ftell(pb);

    put_amf_double(pb, s->duration / AV_TIME_BASE); // fill in the guessed duration, it'll be corrected later if incorrect

    if(video_enc){

        put_amf_string(pb, "width");

        put_amf_double(pb, video_enc->width);

        put_amf_string(pb, "height");

        put_amf_double(pb, video_enc->height);

        put_amf_string(pb, "videodatarate");

        put_amf_double(pb, video_enc->bit_rate / 1024.0);

        put_amf_string(pb, "framerate");

        put_amf_double(pb, framerate);

        put_amf_string(pb, "videocodecid");

        put_amf_double(pb, video_enc->codec_tag);

    }

    if(audio_enc){

        put_amf_string(pb, "audiodatarate");

        put_amf_double(pb, audio_enc->bit_rate / 1024.0);

        put_amf_string(pb, "audiosamplerate");

        put_amf_double(pb, audio_enc->sample_rate);

        put_amf_string(pb, "audiosamplesize");

        put_amf_double(pb, audio_enc->codec_id == CODEC_ID_PCM_U8 ? 8 : 16);

        put_amf_string(pb, "stereo");

        put_amf_bool(pb, audio_enc->channels == 2);

        put_amf_string(pb, "audiocodecid");

        put_amf_double(pb, audio_enc->codec_tag);

    }

    while ((tag = av_metadata_get(s->metadata, "", tag, AV_METADATA_IGNORE_SUFFIX))) {

        put_amf_string(pb, tag->key);

        avio_w8(pb, AMF_DATA_TYPE_STRING);

        put_amf_string(pb, tag->value);

    }

    put_amf_string(pb, "filesize");

    flv->filesize_offset= url_ftell(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= url_ftell(pb) - metadata_size_pos - 10;

    url_fseek(pb, metadata_size_pos, SEEK_SET);

    avio_wb24(pb, data_size);

    url_fseek(pb, data_size + 10 - 3, SEEK_CUR);

    avio_wb32(pb, data_size + 11);

    for (i = 0; i < s->nb_streams; i++) {

        AVCodecContext *enc = s->streams[i]->codec;

        if (enc->codec_id == CODEC_ID_AAC || enc->codec_id == CODEC_ID_H264) {

            int64_t pos;

            avio_w8(pb, enc->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 = url_ftell(pb);

            if (enc->codec_id == CODEC_ID_AAC) {

                avio_w8(pb, get_audio_flags(enc));

                avio_w8(pb, 0); // AAC sequence header

                avio_write(pb, enc->extradata, enc->extradata_size);

            } else {

                avio_w8(pb, enc->codec_tag | FLV_FRAME_KEY); // flags

                avio_w8(pb, 0); // AVC sequence header

                avio_wb24(pb, 0); // composition time

                ff_isom_write_avcc(pb, enc->extradata, enc->extradata_size);

            }

            data_size = url_ftell(pb) - pos;

            url_fseek(pb, -data_size - 10, SEEK_CUR);

            avio_wb24(pb, data_size);

            url_fseek(pb, data_size + 10 - 3, SEEK_CUR);

            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++) {

        AVCodecContext *enc = s->streams[i]->codec;

        if (enc->codec_type == AVMEDIA_TYPE_VIDEO &&

                enc->codec_id == CODEC_ID_H264) {

            put_avc_eos_tag(pb, flv->last_video_ts);

        }

    }

    file_size = url_ftell(pb);

    /* update informations */

    url_fseek(pb, flv->duration_offset, SEEK_SET);

    put_amf_double(pb, flv->duration / (double)1000);

    url_fseek(pb, flv->filesize_offset, SEEK_SET);

    put_amf_double(pb, file_size);

    url_fseek(pb, file_size, SEEK_SET);

    return 0;

}

static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)

{

    AVIOContext *pb = s->pb;

    AVCodecContext *enc = s->streams[pkt->stream_index]->codec;

    FLVContext *flv = s->priv_data;

    unsigned ts;

    int size= pkt->size;

    uint8_t *data= NULL;

    int flags, flags_size;

//    av_log(s, AV_LOG_DEBUG, "type:%d pts: %"PRId64" size:%d\n", enc->codec_type, timestamp, size);

    if(enc->codec_id == CODEC_ID_VP6 || enc->codec_id == CODEC_ID_VP6F ||

       enc->codec_id == CODEC_ID_AAC)

        flags_size= 2;

    else if(enc->codec_id == CODEC_ID_H264)

        flags_size= 5;

    else

        flags_size= 1;

    if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {

        avio_w8(pb, FLV_TAG_TYPE_VIDEO);

        flags = enc->codec_tag;

        if(flags == 0) {

            av_log(enc, AV_LOG_ERROR, "video codec %X not compatible with flv\n",enc->codec_id);

            return -1;

        }

        flags |= pkt->flags & AV_PKT_FLAG_KEY ? FLV_FRAME_KEY : FLV_FRAME_INTER;

    } else {

        assert(enc->codec_type == AVMEDIA_TYPE_AUDIO);

        flags = get_audio_flags(enc);

        assert(size);

        avio_w8(pb, FLV_TAG_TYPE_AUDIO);

    }

    if (enc->codec_id == CODEC_ID_H264) {

        /* check if extradata looks like mp4 formated */

        if (enc->extradata_size > 0 && *(uint8_t*)enc->extradata != 1) {

            if (ff_avc_parse_nal_units_buf(pkt->data, &data, &size) < 0)

                return -1;

        }

        if (!flv->delay && pkt->dts < 0)

            flv->delay = -pkt->dts;

    }

    ts = pkt->dts + flv->delay; // add delay to force positive dts

    if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {

        if (flv->last_video_ts < ts)

            flv->last_video_ts = ts;

    }

    avio_wb24(pb,size + flags_size);

    avio_wb24(pb,ts);

    avio_w8(pb,(ts >> 24) & 0x7F); // timestamps are 32bits _signed_

    avio_wb24(pb,flv->reserved);

    avio_w8(pb,flags);

    if (enc->codec_id == CODEC_ID_VP6)

        avio_w8(pb,0);

    if (enc->codec_id == CODEC_ID_VP6F)

        avio_w8(pb, enc->extradata_size ? enc->extradata[0] : 0);

    else if (enc->codec_id == CODEC_ID_AAC)

        avio_w8(pb,1); // AAC raw

    else if (enc->codec_id == 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);

    put_flush_packet(pb);

    av_free(data);

    return 0;

}

AVOutputFormat ff_flv_muxer = {

    "flv",

    NULL_IF_CONFIG_SMALL("FLV format"),

    "video/x-flv",

    "flv",

    sizeof(FLVContext),

#if CONFIG_LIBMP3LAME

    CODEC_ID_MP3,

#else // CONFIG_LIBMP3LAME

    CODEC_ID_ADPCM_SWF,

#endif // CONFIG_LIBMP3LAME

    CODEC_ID_FLV1,

    flv_write_header,

    flv_write_packet,

    flv_write_trailer,

    .codec_tag= (const AVCodecTag* const []){flv_video_codec_ids, flv_audio_codec_ids, 0},

    .flags= AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,

};