00001 /* 00002 * FLV demuxer 00003 * Copyright (c) 2003 The FFmpeg Project 00004 * 00005 * This demuxer will generate a 1 byte extradata for VP6F content. 00006 * It is composed of: 00007 * - upper 4bits: difference between encoded width and visible width 00008 * - lower 4bits: difference between encoded height and visible height 00009 * 00010 * This file is part of FFmpeg. 00011 * 00012 * FFmpeg is free software; you can redistribute it and/or 00013 * modify it under the terms of the GNU Lesser General Public 00014 * License as published by the Free Software Foundation; either 00015 * version 2.1 of the License, or (at your option) any later version. 00016 * 00017 * FFmpeg is distributed in the hope that it will be useful, 00018 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00019 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00020 * Lesser General Public License for more details. 00021 * 00022 * You should have received a copy of the GNU Lesser General Public 00023 * License along with FFmpeg; if not, write to the Free Software 00024 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00025 */ 00026 00027 #include "libavcodec/mpeg4audio.h" 00028 #include "avformat.h" 00029 #include "flv.h" 00030 00031 typedef struct { 00032 int wrong_dts; 00033 } FLVContext; 00034 00035 static int flv_probe(AVProbeData *p) 00036 { 00037 const uint8_t *d; 00038 00039 d = p->buf; 00040 if (d[0] == 'F' && d[1] == 'L' && d[2] == 'V' && d[3] < 5 && d[5]==0) { 00041 return AVPROBE_SCORE_MAX; 00042 } 00043 return 0; 00044 } 00045 00046 static void flv_set_audio_codec(AVFormatContext *s, AVStream *astream, int flv_codecid) { 00047 AVCodecContext *acodec = astream->codec; 00048 switch(flv_codecid) { 00049 //no distinction between S16 and S8 PCM codec flags 00050 case FLV_CODECID_PCM: 00051 acodec->codec_id = acodec->bits_per_coded_sample == 8 ? CODEC_ID_PCM_S8 : 00052 #ifdef WORDS_BIGENDIAN 00053 CODEC_ID_PCM_S16BE; 00054 #else 00055 CODEC_ID_PCM_S16LE; 00056 #endif 00057 break; 00058 case FLV_CODECID_PCM_LE: 00059 acodec->codec_id = acodec->bits_per_coded_sample == 8 ? CODEC_ID_PCM_S8 : CODEC_ID_PCM_S16LE; break; 00060 case FLV_CODECID_AAC : acodec->codec_id = CODEC_ID_AAC; break; 00061 case FLV_CODECID_ADPCM: acodec->codec_id = CODEC_ID_ADPCM_SWF; break; 00062 case FLV_CODECID_SPEEX: 00063 acodec->codec_id = CODEC_ID_SPEEX; 00064 acodec->sample_rate = 16000; 00065 break; 00066 case FLV_CODECID_MP3 : acodec->codec_id = CODEC_ID_MP3 ; astream->need_parsing = AVSTREAM_PARSE_FULL; break; 00067 case FLV_CODECID_NELLYMOSER_8KHZ_MONO: 00068 acodec->sample_rate = 8000; //in case metadata does not otherwise declare samplerate 00069 case FLV_CODECID_NELLYMOSER: 00070 acodec->codec_id = CODEC_ID_NELLYMOSER; 00071 break; 00072 default: 00073 av_log(s, AV_LOG_INFO, "Unsupported audio codec (%x)\n", flv_codecid >> FLV_AUDIO_CODECID_OFFSET); 00074 acodec->codec_tag = flv_codecid >> FLV_AUDIO_CODECID_OFFSET; 00075 } 00076 } 00077 00078 static int flv_set_video_codec(AVFormatContext *s, AVStream *vstream, int flv_codecid) { 00079 AVCodecContext *vcodec = vstream->codec; 00080 switch(flv_codecid) { 00081 case FLV_CODECID_H263 : vcodec->codec_id = CODEC_ID_FLV1 ; break; 00082 case FLV_CODECID_SCREEN: vcodec->codec_id = CODEC_ID_FLASHSV; break; 00083 case FLV_CODECID_VP6 : vcodec->codec_id = CODEC_ID_VP6F ; 00084 case FLV_CODECID_VP6A : 00085 if(flv_codecid == FLV_CODECID_VP6A) 00086 vcodec->codec_id = CODEC_ID_VP6A; 00087 if(vcodec->extradata_size != 1) { 00088 vcodec->extradata_size = 1; 00089 vcodec->extradata = av_malloc(1); 00090 } 00091 vcodec->extradata[0] = get_byte(s->pb); 00092 return 1; // 1 byte body size adjustment for flv_read_packet() 00093 case FLV_CODECID_H264: 00094 vcodec->codec_id = CODEC_ID_H264; 00095 return 3; // not 4, reading packet type will consume one byte 00096 default: 00097 av_log(s, AV_LOG_INFO, "Unsupported video codec (%x)\n", flv_codecid); 00098 vcodec->codec_tag = flv_codecid; 00099 } 00100 00101 return 0; 00102 } 00103 00104 static int amf_get_string(ByteIOContext *ioc, char *buffer, int buffsize) { 00105 int length = get_be16(ioc); 00106 if(length >= buffsize) { 00107 url_fskip(ioc, length); 00108 return -1; 00109 } 00110 00111 get_buffer(ioc, buffer, length); 00112 00113 buffer[length] = '0円'; 00114 00115 return length; 00116 } 00117 00118 static int amf_parse_object(AVFormatContext *s, AVStream *astream, AVStream *vstream, const char *key, int64_t max_pos, int depth) { 00119 AVCodecContext *acodec, *vcodec; 00120 ByteIOContext *ioc; 00121 AMFDataType amf_type; 00122 char str_val[256]; 00123 double num_val; 00124 00125 num_val = 0; 00126 ioc = s->pb; 00127 00128 amf_type = get_byte(ioc); 00129 00130 switch(amf_type) { 00131 case AMF_DATA_TYPE_NUMBER: 00132 num_val = av_int2dbl(get_be64(ioc)); break; 00133 case AMF_DATA_TYPE_BOOL: 00134 num_val = get_byte(ioc); break; 00135 case AMF_DATA_TYPE_STRING: 00136 if(amf_get_string(ioc, str_val, sizeof(str_val)) < 0) 00137 return -1; 00138 break; 00139 case AMF_DATA_TYPE_OBJECT: { 00140 unsigned int keylen; 00141 00142 while(url_ftell(ioc) < max_pos - 2 && (keylen = get_be16(ioc))) { 00143 url_fskip(ioc, keylen); //skip key string 00144 if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0) 00145 return -1; //if we couldn't skip, bomb out. 00146 } 00147 if(get_byte(ioc) != AMF_END_OF_OBJECT) 00148 return -1; 00149 } 00150 break; 00151 case AMF_DATA_TYPE_NULL: 00152 case AMF_DATA_TYPE_UNDEFINED: 00153 case AMF_DATA_TYPE_UNSUPPORTED: 00154 break; //these take up no additional space 00155 case AMF_DATA_TYPE_MIXEDARRAY: 00156 url_fskip(ioc, 4); //skip 32-bit max array index 00157 while(url_ftell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) { 00158 //this is the only case in which we would want a nested parse to not skip over the object 00159 if(amf_parse_object(s, astream, vstream, str_val, max_pos, depth + 1) < 0) 00160 return -1; 00161 } 00162 if(get_byte(ioc) != AMF_END_OF_OBJECT) 00163 return -1; 00164 break; 00165 case AMF_DATA_TYPE_ARRAY: { 00166 unsigned int arraylen, i; 00167 00168 arraylen = get_be32(ioc); 00169 for(i = 0; i < arraylen && url_ftell(ioc) < max_pos - 1; i++) { 00170 if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0) 00171 return -1; //if we couldn't skip, bomb out. 00172 } 00173 } 00174 break; 00175 case AMF_DATA_TYPE_DATE: 00176 url_fskip(ioc, 8 + 2); //timestamp (double) and UTC offset (int16) 00177 break; 00178 default: //unsupported type, we couldn't skip 00179 return -1; 00180 } 00181 00182 if(depth == 1 && key) { //only look for metadata values when we are not nested and key != NULL 00183 acodec = astream ? astream->codec : NULL; 00184 vcodec = vstream ? vstream->codec : NULL; 00185 00186 if(amf_type == AMF_DATA_TYPE_BOOL) { 00187 if(!strcmp(key, "stereo") && acodec) acodec->channels = num_val > 0 ? 2 : 1; 00188 } else if(amf_type == AMF_DATA_TYPE_NUMBER) { 00189 if(!strcmp(key, "duration")) s->duration = num_val * AV_TIME_BASE; 00190 // else if(!strcmp(key, "width") && vcodec && num_val > 0) vcodec->width = num_val; 00191 // else if(!strcmp(key, "height") && vcodec && num_val > 0) vcodec->height = num_val; 00192 else if(!strcmp(key, "videodatarate") && vcodec && 0 <= (int)(num_val * 1024.0)) 00193 vcodec->bit_rate = num_val * 1024.0; 00194 else if(!strcmp(key, "audiocodecid") && acodec && 0 <= (int)num_val) 00195 flv_set_audio_codec(s, astream, (int)num_val << FLV_AUDIO_CODECID_OFFSET); 00196 else if(!strcmp(key, "videocodecid") && vcodec && 0 <= (int)num_val) 00197 flv_set_video_codec(s, vstream, (int)num_val); 00198 else if(!strcmp(key, "audiosamplesize") && acodec && 0 < (int)num_val) { 00199 acodec->bits_per_coded_sample = num_val; 00200 //we may have to rewrite a previously read codecid because FLV only marks PCM endianness. 00201 if(num_val == 8 && (acodec->codec_id == CODEC_ID_PCM_S16BE || acodec->codec_id == CODEC_ID_PCM_S16LE)) 00202 acodec->codec_id = CODEC_ID_PCM_S8; 00203 } 00204 else if(!strcmp(key, "audiosamplerate") && acodec && num_val >= 0) { 00205 //some tools, like FLVTool2, write consistently approximate metadata sample rates 00206 if (!acodec->sample_rate) { 00207 switch((int)num_val) { 00208 case 44000: acodec->sample_rate = 44100 ; break; 00209 case 22000: acodec->sample_rate = 22050 ; break; 00210 case 11000: acodec->sample_rate = 11025 ; break; 00211 case 5000 : acodec->sample_rate = 5512 ; break; 00212 default : acodec->sample_rate = num_val; 00213 } 00214 } 00215 } 00216 } 00217 } 00218 00219 return 0; 00220 } 00221 00222 static int flv_read_metabody(AVFormatContext *s, int64_t next_pos) { 00223 AMFDataType type; 00224 AVStream *stream, *astream, *vstream; 00225 ByteIOContext *ioc; 00226 int i, keylen; 00227 char buffer[11]; //only needs to hold the string "onMetaData". Anything longer is something we don't want. 00228 00229 astream = NULL; 00230 vstream = NULL; 00231 keylen = 0; 00232 ioc = s->pb; 00233 00234 //first object needs to be "onMetaData" string 00235 type = get_byte(ioc); 00236 if(type != AMF_DATA_TYPE_STRING || amf_get_string(ioc, buffer, sizeof(buffer)) < 0 || strcmp(buffer, "onMetaData")) 00237 return -1; 00238 00239 //find the streams now so that amf_parse_object doesn't need to do the lookup every time it is called. 00240 for(i = 0; i < s->nb_streams; i++) { 00241 stream = s->streams[i]; 00242 if (stream->codec->codec_type == CODEC_TYPE_AUDIO) astream = stream; 00243 else if(stream->codec->codec_type == CODEC_TYPE_VIDEO) vstream = stream; 00244 } 00245 00246 //parse the second object (we want a mixed array) 00247 if(amf_parse_object(s, astream, vstream, buffer, next_pos, 0) < 0) 00248 return -1; 00249 00250 return 0; 00251 } 00252 00253 static AVStream *create_stream(AVFormatContext *s, int is_audio){ 00254 AVStream *st = av_new_stream(s, is_audio); 00255 if (!st) 00256 return NULL; 00257 st->codec->codec_type = is_audio ? CODEC_TYPE_AUDIO : CODEC_TYPE_VIDEO; 00258 av_set_pts_info(st, 32, 1, 1000); /* 32 bit pts in ms */ 00259 return st; 00260 } 00261 00262 static int flv_read_header(AVFormatContext *s, 00263 AVFormatParameters *ap) 00264 { 00265 int offset, flags; 00266 00267 url_fskip(s->pb, 4); 00268 flags = get_byte(s->pb); 00269 /* old flvtool cleared this field */ 00270 /* FIXME: better fix needed */ 00271 if (!flags) { 00272 flags = FLV_HEADER_FLAG_HASVIDEO | FLV_HEADER_FLAG_HASAUDIO; 00273 av_log(s, AV_LOG_WARNING, "Broken FLV file, which says no streams present, this might fail\n"); 00274 } 00275 00276 if((flags & (FLV_HEADER_FLAG_HASVIDEO|FLV_HEADER_FLAG_HASAUDIO)) 00277 != (FLV_HEADER_FLAG_HASVIDEO|FLV_HEADER_FLAG_HASAUDIO)) 00278 s->ctx_flags |= AVFMTCTX_NOHEADER; 00279 00280 if(flags & FLV_HEADER_FLAG_HASVIDEO){ 00281 if(!create_stream(s, 0)) 00282 return AVERROR(ENOMEM); 00283 } 00284 if(flags & FLV_HEADER_FLAG_HASAUDIO){ 00285 if(!create_stream(s, 1)) 00286 return AVERROR(ENOMEM); 00287 } 00288 00289 offset = get_be32(s->pb); 00290 url_fseek(s->pb, offset, SEEK_SET); 00291 00292 s->start_time = 0; 00293 00294 return 0; 00295 } 00296 00297 static int flv_get_extradata(AVFormatContext *s, AVStream *st, int size) 00298 { 00299 av_free(st->codec->extradata); 00300 st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE); 00301 if (!st->codec->extradata) 00302 return AVERROR(ENOMEM); 00303 st->codec->extradata_size = size; 00304 get_buffer(s->pb, st->codec->extradata, st->codec->extradata_size); 00305 return 0; 00306 } 00307 00308 static int flv_read_packet(AVFormatContext *s, AVPacket *pkt) 00309 { 00310 FLVContext *flv = s->priv_data; 00311 int ret, i, type, size, flags, is_audio; 00312 int64_t next, pos; 00313 int64_t dts, pts = AV_NOPTS_VALUE; 00314 AVStream *st = NULL; 00315 00316 retry: 00317 for(;;){ 00318 pos = url_ftell(s->pb); 00319 url_fskip(s->pb, 4); /* size of previous packet */ 00320 type = get_byte(s->pb); 00321 size = get_be24(s->pb); 00322 dts = get_be24(s->pb); 00323 dts |= get_byte(s->pb) << 24; 00324 // av_log(s, AV_LOG_DEBUG, "type:%d, size:%d, dts:%d\n", type, size, dts); 00325 if (url_feof(s->pb)) 00326 return AVERROR_EOF; 00327 url_fskip(s->pb, 3); /* stream id, always 0 */ 00328 flags = 0; 00329 00330 if(size == 0) 00331 continue; 00332 00333 next= size + url_ftell(s->pb); 00334 00335 if (type == FLV_TAG_TYPE_AUDIO) { 00336 is_audio=1; 00337 flags = get_byte(s->pb); 00338 size--; 00339 } else if (type == FLV_TAG_TYPE_VIDEO) { 00340 is_audio=0; 00341 flags = get_byte(s->pb); 00342 size--; 00343 if ((flags & 0xf0) == 0x50) /* video info / command frame */ 00344 goto skip; 00345 } else { 00346 if (type == FLV_TAG_TYPE_META && size > 13+1+4) 00347 flv_read_metabody(s, next); 00348 else /* skip packet */ 00349 av_log(s, AV_LOG_ERROR, "skipping flv packet: type %d, size %d, flags %d\n", type, size, flags); 00350 skip: 00351 url_fseek(s->pb, next, SEEK_SET); 00352 continue; 00353 } 00354 00355 /* skip empty data packets */ 00356 if (!size) 00357 continue; 00358 00359 /* now find stream */ 00360 for(i=0;i<s->nb_streams;i++) { 00361 st = s->streams[i]; 00362 if (st->id == is_audio) 00363 break; 00364 } 00365 if(i == s->nb_streams){ 00366 av_log(s, AV_LOG_ERROR, "invalid stream\n"); 00367 st= create_stream(s, is_audio); 00368 s->ctx_flags &= ~AVFMTCTX_NOHEADER; 00369 } 00370 // av_log(s, AV_LOG_DEBUG, "%d %X %d \n", is_audio, flags, st->discard); 00371 if( (st->discard >= AVDISCARD_NONKEY && !((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY || is_audio)) 00372 ||(st->discard >= AVDISCARD_BIDIR && ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_DISP_INTER && !is_audio)) 00373 || st->discard >= AVDISCARD_ALL 00374 ){ 00375 url_fseek(s->pb, next, SEEK_SET); 00376 continue; 00377 } 00378 if ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY) 00379 av_add_index_entry(st, pos, dts, size, 0, AVINDEX_KEYFRAME); 00380 break; 00381 } 00382 00383 // if not streamed and no duration from metadata then seek to end to find the duration from the timestamps 00384 if(!url_is_streamed(s->pb) && s->duration==AV_NOPTS_VALUE){ 00385 int size; 00386 const int64_t pos= url_ftell(s->pb); 00387 const int64_t fsize= url_fsize(s->pb); 00388 url_fseek(s->pb, fsize-4, SEEK_SET); 00389 size= get_be32(s->pb); 00390 url_fseek(s->pb, fsize-3-size, SEEK_SET); 00391 if(size == get_be24(s->pb) + 11){ 00392 s->duration= get_be24(s->pb) * (int64_t)AV_TIME_BASE / 1000; 00393 } 00394 url_fseek(s->pb, pos, SEEK_SET); 00395 } 00396 00397 if(is_audio){ 00398 if(!st->codec->channels || !st->codec->sample_rate || !st->codec->bits_per_coded_sample) { 00399 st->codec->channels = (flags & FLV_AUDIO_CHANNEL_MASK) == FLV_STEREO ? 2 : 1; 00400 st->codec->sample_rate = (44100 << ((flags & FLV_AUDIO_SAMPLERATE_MASK) >> FLV_AUDIO_SAMPLERATE_OFFSET) >> 3); 00401 st->codec->bits_per_coded_sample = (flags & FLV_AUDIO_SAMPLESIZE_MASK) ? 16 : 8; 00402 } 00403 if(!st->codec->codec_id){ 00404 flv_set_audio_codec(s, st, flags & FLV_AUDIO_CODECID_MASK); 00405 } 00406 }else{ 00407 size -= flv_set_video_codec(s, st, flags & FLV_VIDEO_CODECID_MASK); 00408 } 00409 00410 if (st->codec->codec_id == CODEC_ID_AAC || 00411 st->codec->codec_id == CODEC_ID_H264) { 00412 int type = get_byte(s->pb); 00413 size--; 00414 if (st->codec->codec_id == CODEC_ID_H264) { 00415 int32_t cts = (get_be24(s->pb)+0xff800000)^0xff800000; // sign extension 00416 pts = dts + cts; 00417 if (cts < 0) { // dts are wrong 00418 flv->wrong_dts = 1; 00419 av_log(s, AV_LOG_WARNING, "negative cts, previous timestamps might be wrong\n"); 00420 } 00421 if (flv->wrong_dts) 00422 dts = AV_NOPTS_VALUE; 00423 } 00424 if (type == 0) { 00425 if ((ret = flv_get_extradata(s, st, size)) < 0) 00426 return ret; 00427 if (st->codec->codec_id == CODEC_ID_AAC) { 00428 MPEG4AudioConfig cfg; 00429 ff_mpeg4audio_get_config(&cfg, st->codec->extradata, 00430 st->codec->extradata_size); 00431 if (cfg.chan_config > 7) 00432 return -1; 00433 st->codec->channels = ff_mpeg4audio_channels[cfg.chan_config]; 00434 st->codec->sample_rate = cfg.sample_rate; 00435 dprintf(s, "mp4a config channels %d sample rate %d\n", 00436 st->codec->channels, st->codec->sample_rate); 00437 } 00438 00439 goto retry; 00440 } 00441 } 00442 00443 ret= av_get_packet(s->pb, pkt, size); 00444 if (ret <= 0) { 00445 return AVERROR(EIO); 00446 } 00447 /* note: we need to modify the packet size here to handle the last 00448 packet */ 00449 pkt->size = ret; 00450 pkt->dts = dts; 00451 pkt->pts = pts == AV_NOPTS_VALUE ? dts : pts; 00452 pkt->stream_index = st->index; 00453 00454 if (is_audio || ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY)) 00455 pkt->flags |= PKT_FLAG_KEY; 00456 00457 return ret; 00458 } 00459 00460 AVInputFormat flv_demuxer = { 00461 "flv", 00462 NULL_IF_CONFIG_SMALL("FLV format"), 00463 sizeof(FLVContext), 00464 flv_probe, 00465 flv_read_header, 00466 flv_read_packet, 00467 .extensions = "flv", 00468 .value = CODEC_ID_FLV1, 00469 };