libavformat/flvenc.c

   1 /*
   2  * FLV encoder.
   3  * Copyright (c) 2003 The FFmpeg Project.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19 #include "avformat.h"
  20
  21 #undef NDEBUG
  22 #include <assert.h>
  23
  24 typedef struct FLVContext {
  25     int hasAudio;
  26     int hasVideo;
  27     int reserved;
  28 } FLVContext;
  29
  30 static void put_be24(ByteIOContext *pb, int value)
  31 {
  32     put_byte(pb, (value>>16) & 0xFF );
  33     put_byte(pb, (value>> 8) & 0xFF );
  34     put_byte(pb, (value>> 0) & 0xFF );
  35 }
  36
  37 static int get_audio_flags(AVCodecContext *enc){
  38     int flags = (enc->bits_per_sample == 16) ? 0x2 : 0x0;
  39
  40     switch (enc->sample_rate) {
  41         case    44100:
  42             flags |= 0x0C;
  43             break;
  44         case    22050:
  45             flags |= 0x08;
  46             break;
  47         case    11025:
  48             flags |= 0x04;
  49             break;
  50         case     8000: //nellymoser only
  51         case     5512: //not mp3
  52             flags |= 0x00;
  53             break;
  54         default:
  55             return -1;
  56     }
  57
  58     if (enc->channels > 1) {
  59         flags |= 0x01;
  60     }
  61
  62     switch(enc->codec_id){
  63     case CODEC_ID_MP3:
  64         flags |= 0x20 | 0x2;
  65         break;
  66     case CODEC_ID_PCM_S8:
  67         break;
  68     case CODEC_ID_PCM_S16BE:
  69         flags |= 0x60 | 0x2;
  70         break;
  71     case CODEC_ID_PCM_S16LE:
  72         flags |= 0x2;
  73         break;
  74     case 0:
  75         flags |= enc->codec_tag<<4;
  76         break;
  77     default:
  78         return -1;
  79     }
  80
  81     return flags;
  82 }
  83
  84 static int flv_write_header(AVFormatContext *s)
  85 {
  86     ByteIOContext *pb = &s->pb;
  87     FLVContext *flv = s->priv_data;
  88     int i;
  89
  90     flv->hasAudio = 0;
  91     flv->hasVideo = 0;
  92
  93     put_tag(pb,"FLV");
  94     put_byte(pb,1);
  95     put_byte(pb,0); // delayed write
  96     put_be32(pb,9);
  97     put_be32(pb,0);
  98
  99     for(i=0; i<s->nb_streams; i++){
 100         AVCodecContext *enc = s->streams[i]->codec;
 101         av_set_pts_info(s->streams[i], 24, 1, 1000); /* 24 bit pts in ms */
 102         if(enc->codec_tag == 5){
 103             put_byte(pb,8); // message type
 104             put_be24(pb,0); // include flags
 105             put_be24(pb,0); // time stamp
 106             put_be32(pb,0); // reserved
 107             put_be32(pb,11); // size
 108             flv->reserved=5;
 109         }
 110         if(enc->codec_type == CODEC_TYPE_AUDIO && get_audio_flags(enc)<0)
 111             return -1;
 112     }
 113
 114     return 0;
 115 }
 116
 117 static int flv_write_trailer(AVFormatContext *s)
 118 {
 119     int64_t file_size;
 120     int flags = 0;
 121
 122     ByteIOContext *pb = &s->pb;
 123     FLVContext *flv = s->priv_data;
 124
 125     file_size = url_ftell(pb);
 126     flags |= flv->hasAudio ? 4 : 0;
 127     flags |= flv->hasVideo ? 1 : 0;
 128     url_fseek(pb, 4, SEEK_SET);
 129     put_byte(pb,flags);
 130     url_fseek(pb, file_size, SEEK_SET);
 131     return 0;
 132 }
 133
 134 static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
 135 {
 136     ByteIOContext *pb = &s->pb;
 137     AVCodecContext *enc = s->streams[pkt->stream_index]->codec;
 138     FLVContext *flv = s->priv_data;
 139     int size= pkt->size;
 140     int flags;
 141
 142 //    av_log(s, AV_LOG_DEBUG, "type:%d pts: %lld size:%d\n", enc->codec_type, timestamp, size);
 143
 144     if (enc->codec_type == CODEC_TYPE_VIDEO) {
 145         put_byte(pb, 9);
 146         flags = 2; // choose h263
 147         flags |= pkt->flags & PKT_FLAG_KEY ? 0x10 : 0x20; // add keyframe indicator
 148         flv->hasVideo = 1;
 149     } else {
 150         assert(enc->codec_type == CODEC_TYPE_AUDIO);
 151         flags = get_audio_flags(enc);
 152
 153         assert(size);
 154
 155         put_byte(pb, 8);
 156
 157         // We got audio! Make sure we set this to the global flags on closure
 158         flv->hasAudio = 1;
 159     }
 160
 161     put_be24(pb,size+1); // include flags
 162     put_be24(pb,pkt->pts);
 163     put_be32(pb,flv->reserved);
 164     put_byte(pb,flags);
 165     put_buffer(pb, pkt->data, size);
 166     put_be32(pb,size+1+11); // previous tag size
 167
 168     put_flush_packet(pb);
 169     return 0;
 170 }
 171
 172 static AVOutputFormat flv_oformat = {
 173     "flv",
 174     "flv format",
 175     "video/x-flv",
 176     "flv",
 177     sizeof(FLVContext),
 178 #ifdef CONFIG_MP3LAME
 179     CODEC_ID_MP3,
 180 #else // CONFIG_MP3LAME
 181     CODEC_ID_NONE,
 182 #endif // CONFIG_MP3LAME
 183     CODEC_ID_FLV1,
 184     flv_write_header,
 185     flv_write_packet,
 186     flv_write_trailer,
 187 };
 188
 189 int flvenc_init(void)
 190 {
 191     av_register_output_format(&flv_oformat);
 192     return 0;
 193 }