Libav
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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 "libavutil/avstring.h" 00028 #include "libavcodec/bytestream.h" 00029 #include "libavcodec/mpeg4audio.h" 00030 #include "avformat.h" 00031 #include "flv.h" 00032 00033 typedef struct { 00034 int wrong_dts; 00035 } FLVContext; 00036 00037 static int flv_probe(AVProbeData *p) 00038 { 00039 const uint8_t *d; 00040 00041 d = p->buf; 00042 if (d[0] == 'F' && d[1] == 'L' && d[2] == 'V' && d[3] < 5 && d[5]==0 && AV_RB32(d+5)>8) { 00043 return AVPROBE_SCORE_MAX; 00044 } 00045 return 0; 00046 } 00047 00048 static void flv_set_audio_codec(AVFormatContext *s, AVStream *astream, int flv_codecid) { 00049 AVCodecContext *acodec = astream->codec; 00050 switch(flv_codecid) { 00051 //no distinction between S16 and S8 PCM codec flags 00052 case FLV_CODECID_PCM: 00053 acodec->codec_id = acodec->bits_per_coded_sample == 8 ? CODEC_ID_PCM_U8 : 00054 #if HAVE_BIGENDIAN 00055 CODEC_ID_PCM_S16BE; 00056 #else 00057 CODEC_ID_PCM_S16LE; 00058 #endif 00059 break; 00060 case FLV_CODECID_PCM_LE: 00061 acodec->codec_id = acodec->bits_per_coded_sample == 8 ? CODEC_ID_PCM_U8 : CODEC_ID_PCM_S16LE; break; 00062 case FLV_CODECID_AAC : acodec->codec_id = CODEC_ID_AAC; break; 00063 case FLV_CODECID_ADPCM: acodec->codec_id = CODEC_ID_ADPCM_SWF; break; 00064 case FLV_CODECID_SPEEX: 00065 acodec->codec_id = CODEC_ID_SPEEX; 00066 acodec->sample_rate = 16000; 00067 break; 00068 case FLV_CODECID_MP3 : acodec->codec_id = CODEC_ID_MP3 ; astream->need_parsing = AVSTREAM_PARSE_FULL; break; 00069 case FLV_CODECID_NELLYMOSER_8KHZ_MONO: 00070 acodec->sample_rate = 8000; //in case metadata does not otherwise declare samplerate 00071 case FLV_CODECID_NELLYMOSER: 00072 acodec->codec_id = CODEC_ID_NELLYMOSER; 00073 break; 00074 default: 00075 av_log(s, AV_LOG_INFO, "Unsupported audio codec (%x)\n", flv_codecid >> FLV_AUDIO_CODECID_OFFSET); 00076 acodec->codec_tag = flv_codecid >> FLV_AUDIO_CODECID_OFFSET; 00077 } 00078 } 00079 00080 static int flv_set_video_codec(AVFormatContext *s, AVStream *vstream, int flv_codecid) { 00081 AVCodecContext *vcodec = vstream->codec; 00082 switch(flv_codecid) { 00083 case FLV_CODECID_H263 : vcodec->codec_id = CODEC_ID_FLV1 ; break; 00084 case FLV_CODECID_SCREEN: vcodec->codec_id = CODEC_ID_FLASHSV; break; 00085 case FLV_CODECID_SCREEN2: vcodec->codec_id = CODEC_ID_FLASHSV2; break; 00086 case FLV_CODECID_VP6 : vcodec->codec_id = CODEC_ID_VP6F ; 00087 case FLV_CODECID_VP6A : 00088 if(flv_codecid == FLV_CODECID_VP6A) 00089 vcodec->codec_id = CODEC_ID_VP6A; 00090 if(vcodec->extradata_size != 1) { 00091 vcodec->extradata_size = 1; 00092 vcodec->extradata = av_malloc(1); 00093 } 00094 vcodec->extradata[0] = get_byte(s->pb); 00095 return 1; // 1 byte body size adjustment for flv_read_packet() 00096 case FLV_CODECID_H264: 00097 vcodec->codec_id = CODEC_ID_H264; 00098 return 3; // not 4, reading packet type will consume one byte 00099 default: 00100 av_log(s, AV_LOG_INFO, "Unsupported video codec (%x)\n", flv_codecid); 00101 vcodec->codec_tag = flv_codecid; 00102 } 00103 00104 return 0; 00105 } 00106 00107 static int amf_get_string(ByteIOContext *ioc, char *buffer, int buffsize) { 00108 int length = get_be16(ioc); 00109 if(length >= buffsize) { 00110 url_fskip(ioc, length); 00111 return -1; 00112 } 00113 00114 get_buffer(ioc, buffer, length); 00115 00116 buffer[length] = '\0'; 00117 00118 return length; 00119 } 00120 00121 static int amf_parse_object(AVFormatContext *s, AVStream *astream, AVStream *vstream, const char *key, int64_t max_pos, int depth) { 00122 AVCodecContext *acodec, *vcodec; 00123 ByteIOContext *ioc; 00124 AMFDataType amf_type; 00125 char str_val[256]; 00126 double num_val; 00127 00128 num_val = 0; 00129 ioc = s->pb; 00130 00131 amf_type = get_byte(ioc); 00132 00133 switch(amf_type) { 00134 case AMF_DATA_TYPE_NUMBER: 00135 num_val = av_int2dbl(get_be64(ioc)); break; 00136 case AMF_DATA_TYPE_BOOL: 00137 num_val = get_byte(ioc); break; 00138 case AMF_DATA_TYPE_STRING: 00139 if(amf_get_string(ioc, str_val, sizeof(str_val)) < 0) 00140 return -1; 00141 break; 00142 case AMF_DATA_TYPE_OBJECT: { 00143 unsigned int keylen; 00144 00145 while(url_ftell(ioc) < max_pos - 2 && (keylen = get_be16(ioc))) { 00146 url_fskip(ioc, keylen); //skip key string 00147 if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0) 00148 return -1; //if we couldn't skip, bomb out. 00149 } 00150 if(get_byte(ioc) != AMF_END_OF_OBJECT) 00151 return -1; 00152 } 00153 break; 00154 case AMF_DATA_TYPE_NULL: 00155 case AMF_DATA_TYPE_UNDEFINED: 00156 case AMF_DATA_TYPE_UNSUPPORTED: 00157 break; //these take up no additional space 00158 case AMF_DATA_TYPE_MIXEDARRAY: 00159 url_fskip(ioc, 4); //skip 32-bit max array index 00160 while(url_ftell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) { 00161 //this is the only case in which we would want a nested parse to not skip over the object 00162 if(amf_parse_object(s, astream, vstream, str_val, max_pos, depth + 1) < 0) 00163 return -1; 00164 } 00165 if(get_byte(ioc) != AMF_END_OF_OBJECT) 00166 return -1; 00167 break; 00168 case AMF_DATA_TYPE_ARRAY: { 00169 unsigned int arraylen, i; 00170 00171 arraylen = get_be32(ioc); 00172 for(i = 0; i < arraylen && url_ftell(ioc) < max_pos - 1; i++) { 00173 if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0) 00174 return -1; //if we couldn't skip, bomb out. 00175 } 00176 } 00177 break; 00178 case AMF_DATA_TYPE_DATE: 00179 url_fskip(ioc, 8 + 2); //timestamp (double) and UTC offset (int16) 00180 break; 00181 default: //unsupported type, we couldn't skip 00182 return -1; 00183 } 00184 00185 if(depth == 1 && key) { //only look for metadata values when we are not nested and key != NULL 00186 acodec = astream ? astream->codec : NULL; 00187 vcodec = vstream ? vstream->codec : NULL; 00188 00189 if(amf_type == AMF_DATA_TYPE_BOOL) { 00190 av_strlcpy(str_val, num_val > 0 ? "true" : "false", sizeof(str_val)); 00191 av_metadata_set2(&s->metadata, key, str_val, 0); 00192 } else if(amf_type == AMF_DATA_TYPE_NUMBER) { 00193 snprintf(str_val, sizeof(str_val), "%.f", num_val); 00194 av_metadata_set2(&s->metadata, key, str_val, 0); 00195 if(!strcmp(key, "duration")) s->duration = num_val * AV_TIME_BASE; 00196 else if(!strcmp(key, "videodatarate") && vcodec && 0 <= (int)(num_val * 1024.0)) 00197 vcodec->bit_rate = num_val * 1024.0; 00198 else if(!strcmp(key, "audiodatarate") && acodec && 0 <= (int)(num_val * 1024.0)) 00199 acodec->bit_rate = num_val * 1024.0; 00200 } else if (amf_type == AMF_DATA_TYPE_STRING) 00201 av_metadata_set2(&s->metadata, key, str_val, 0); 00202 } 00203 00204 return 0; 00205 } 00206 00207 static int flv_read_metabody(AVFormatContext *s, int64_t next_pos) { 00208 AMFDataType type; 00209 AVStream *stream, *astream, *vstream; 00210 ByteIOContext *ioc; 00211 int i; 00212 char buffer[11]; //only needs to hold the string "onMetaData". Anything longer is something we don't want. 00213 00214 astream = NULL; 00215 vstream = NULL; 00216 ioc = s->pb; 00217 00218 //first object needs to be "onMetaData" string 00219 type = get_byte(ioc); 00220 if(type != AMF_DATA_TYPE_STRING || amf_get_string(ioc, buffer, sizeof(buffer)) < 0 || strcmp(buffer, "onMetaData")) 00221 return -1; 00222 00223 //find the streams now so that amf_parse_object doesn't need to do the lookup every time it is called. 00224 for(i = 0; i < s->nb_streams; i++) { 00225 stream = s->streams[i]; 00226 if (stream->codec->codec_type == AVMEDIA_TYPE_AUDIO) astream = stream; 00227 else if(stream->codec->codec_type == AVMEDIA_TYPE_VIDEO) vstream = stream; 00228 } 00229 00230 //parse the second object (we want a mixed array) 00231 if(amf_parse_object(s, astream, vstream, buffer, next_pos, 0) < 0) 00232 return -1; 00233 00234 return 0; 00235 } 00236 00237 static AVStream *create_stream(AVFormatContext *s, int is_audio){ 00238 AVStream *st = av_new_stream(s, is_audio); 00239 if (!st) 00240 return NULL; 00241 st->codec->codec_type = is_audio ? AVMEDIA_TYPE_AUDIO : AVMEDIA_TYPE_VIDEO; 00242 av_set_pts_info(st, 32, 1, 1000); /* 32 bit pts in ms */ 00243 return st; 00244 } 00245 00246 static int flv_read_header(AVFormatContext *s, 00247 AVFormatParameters *ap) 00248 { 00249 int offset, flags; 00250 00251 url_fskip(s->pb, 4); 00252 flags = get_byte(s->pb); 00253 /* old flvtool cleared this field */ 00254 /* FIXME: better fix needed */ 00255 if (!flags) { 00256 flags = FLV_HEADER_FLAG_HASVIDEO | FLV_HEADER_FLAG_HASAUDIO; 00257 av_log(s, AV_LOG_WARNING, "Broken FLV file, which says no streams present, this might fail\n"); 00258 } 00259 00260 if((flags & (FLV_HEADER_FLAG_HASVIDEO|FLV_HEADER_FLAG_HASAUDIO)) 00261 != (FLV_HEADER_FLAG_HASVIDEO|FLV_HEADER_FLAG_HASAUDIO)) 00262 s->ctx_flags |= AVFMTCTX_NOHEADER; 00263 00264 if(flags & FLV_HEADER_FLAG_HASVIDEO){ 00265 if(!create_stream(s, 0)) 00266 return AVERROR(ENOMEM); 00267 } 00268 if(flags & FLV_HEADER_FLAG_HASAUDIO){ 00269 if(!create_stream(s, 1)) 00270 return AVERROR(ENOMEM); 00271 } 00272 00273 offset = get_be32(s->pb); 00274 url_fseek(s->pb, offset, SEEK_SET); 00275 url_fskip(s->pb, 4); 00276 00277 s->start_time = 0; 00278 00279 return 0; 00280 } 00281 00282 static int flv_get_extradata(AVFormatContext *s, AVStream *st, int size) 00283 { 00284 av_free(st->codec->extradata); 00285 st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE); 00286 if (!st->codec->extradata) 00287 return AVERROR(ENOMEM); 00288 st->codec->extradata_size = size; 00289 get_buffer(s->pb, st->codec->extradata, st->codec->extradata_size); 00290 return 0; 00291 } 00292 00293 static int flv_read_packet(AVFormatContext *s, AVPacket *pkt) 00294 { 00295 FLVContext *flv = s->priv_data; 00296 int ret, i, type, size, flags, is_audio; 00297 int64_t next, pos; 00298 int64_t dts, pts = AV_NOPTS_VALUE; 00299 AVStream *st = NULL; 00300 00301 for(;;url_fskip(s->pb, 4)){ /* pkt size is repeated at end. skip it */ 00302 pos = url_ftell(s->pb); 00303 type = get_byte(s->pb); 00304 size = get_be24(s->pb); 00305 dts = get_be24(s->pb); 00306 dts |= get_byte(s->pb) << 24; 00307 // av_log(s, AV_LOG_DEBUG, "type:%d, size:%d, dts:%d\n", type, size, dts); 00308 if (url_feof(s->pb)) 00309 return AVERROR_EOF; 00310 url_fskip(s->pb, 3); /* stream id, always 0 */ 00311 flags = 0; 00312 00313 if(size == 0) 00314 continue; 00315 00316 next= size + url_ftell(s->pb); 00317 00318 if (type == FLV_TAG_TYPE_AUDIO) { 00319 is_audio=1; 00320 flags = get_byte(s->pb); 00321 size--; 00322 } else if (type == FLV_TAG_TYPE_VIDEO) { 00323 is_audio=0; 00324 flags = get_byte(s->pb); 00325 size--; 00326 if ((flags & 0xf0) == 0x50) /* video info / command frame */ 00327 goto skip; 00328 } else { 00329 if (type == FLV_TAG_TYPE_META && size > 13+1+4) 00330 flv_read_metabody(s, next); 00331 else /* skip packet */ 00332 av_log(s, AV_LOG_DEBUG, "skipping flv packet: type %d, size %d, flags %d\n", type, size, flags); 00333 skip: 00334 url_fseek(s->pb, next, SEEK_SET); 00335 continue; 00336 } 00337 00338 /* skip empty data packets */ 00339 if (!size) 00340 continue; 00341 00342 /* now find stream */ 00343 for(i=0;i<s->nb_streams;i++) { 00344 st = s->streams[i]; 00345 if (st->id == is_audio) 00346 break; 00347 } 00348 if(i == s->nb_streams){ 00349 av_log(s, AV_LOG_ERROR, "invalid stream\n"); 00350 st= create_stream(s, is_audio); 00351 s->ctx_flags &= ~AVFMTCTX_NOHEADER; 00352 } 00353 // av_log(s, AV_LOG_DEBUG, "%d %X %d \n", is_audio, flags, st->discard); 00354 if( (st->discard >= AVDISCARD_NONKEY && !((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY || is_audio)) 00355 ||(st->discard >= AVDISCARD_BIDIR && ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_DISP_INTER && !is_audio)) 00356 || st->discard >= AVDISCARD_ALL 00357 ){ 00358 url_fseek(s->pb, next, SEEK_SET); 00359 continue; 00360 } 00361 if ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY) 00362 av_add_index_entry(st, pos, dts, size, 0, AVINDEX_KEYFRAME); 00363 break; 00364 } 00365 00366 // if not streamed and no duration from metadata then seek to end to find the duration from the timestamps 00367 if(!url_is_streamed(s->pb) && (!s->duration || s->duration==AV_NOPTS_VALUE)){ 00368 int size; 00369 const int64_t pos= url_ftell(s->pb); 00370 const int64_t fsize= url_fsize(s->pb); 00371 url_fseek(s->pb, fsize-4, SEEK_SET); 00372 size= get_be32(s->pb); 00373 url_fseek(s->pb, fsize-3-size, SEEK_SET); 00374 if(size == get_be24(s->pb) + 11){ 00375 uint32_t ts = get_be24(s->pb); 00376 ts |= get_byte(s->pb) << 24; 00377 s->duration = ts * (int64_t)AV_TIME_BASE / 1000; 00378 } 00379 url_fseek(s->pb, pos, SEEK_SET); 00380 } 00381 00382 if(is_audio){ 00383 if(!st->codec->channels || !st->codec->sample_rate || !st->codec->bits_per_coded_sample) { 00384 st->codec->channels = (flags & FLV_AUDIO_CHANNEL_MASK) == FLV_STEREO ? 2 : 1; 00385 st->codec->sample_rate = (44100 << ((flags & FLV_AUDIO_SAMPLERATE_MASK) >> FLV_AUDIO_SAMPLERATE_OFFSET) >> 3); 00386 st->codec->bits_per_coded_sample = (flags & FLV_AUDIO_SAMPLESIZE_MASK) ? 16 : 8; 00387 } 00388 if(!st->codec->codec_id){ 00389 flv_set_audio_codec(s, st, flags & FLV_AUDIO_CODECID_MASK); 00390 } 00391 }else{ 00392 size -= flv_set_video_codec(s, st, flags & FLV_VIDEO_CODECID_MASK); 00393 } 00394 00395 if (st->codec->codec_id == CODEC_ID_AAC || 00396 st->codec->codec_id == CODEC_ID_H264) { 00397 int type = get_byte(s->pb); 00398 size--; 00399 if (st->codec->codec_id == CODEC_ID_H264) { 00400 int32_t cts = (get_be24(s->pb)+0xff800000)^0xff800000; // sign extension 00401 pts = dts + cts; 00402 if (cts < 0) { // dts are wrong 00403 flv->wrong_dts = 1; 00404 av_log(s, AV_LOG_WARNING, "negative cts, previous timestamps might be wrong\n"); 00405 } 00406 if (flv->wrong_dts) 00407 dts = AV_NOPTS_VALUE; 00408 } 00409 if (type == 0) { 00410 if ((ret = flv_get_extradata(s, st, size)) < 0) 00411 return ret; 00412 if (st->codec->codec_id == CODEC_ID_AAC) { 00413 MPEG4AudioConfig cfg; 00414 ff_mpeg4audio_get_config(&cfg, st->codec->extradata, 00415 st->codec->extradata_size); 00416 st->codec->channels = cfg.channels; 00417 st->codec->sample_rate = cfg.sample_rate; 00418 dprintf(s, "mp4a config channels %d sample rate %d\n", 00419 st->codec->channels, st->codec->sample_rate); 00420 } 00421 00422 ret = AVERROR(EAGAIN); 00423 goto leave; 00424 } 00425 } 00426 00427 /* skip empty data packets */ 00428 if (!size) { 00429 ret = AVERROR(EAGAIN); 00430 goto leave; 00431 } 00432 00433 ret= av_get_packet(s->pb, pkt, size); 00434 if (ret < 0) { 00435 return AVERROR(EIO); 00436 } 00437 /* note: we need to modify the packet size here to handle the last 00438 packet */ 00439 pkt->size = ret; 00440 pkt->dts = dts; 00441 pkt->pts = pts == AV_NOPTS_VALUE ? dts : pts; 00442 pkt->stream_index = st->index; 00443 00444 if (is_audio || ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY)) 00445 pkt->flags |= AV_PKT_FLAG_KEY; 00446 00447 leave: 00448 url_fskip(s->pb, 4); 00449 return ret; 00450 } 00451 00452 static int flv_read_seek(AVFormatContext *s, int stream_index, 00453 int64_t ts, int flags) 00454 { 00455 return av_url_read_fseek(s->pb, stream_index, ts, flags); 00456 } 00457 00458 #if 0 /* don't know enough to implement this */ 00459 static int flv_read_seek2(AVFormatContext *s, int stream_index, 00460 int64_t min_ts, int64_t ts, int64_t max_ts, int flags) 00461 { 00462 int ret = AVERROR(ENOSYS); 00463 00464 if (ts - min_ts > (uint64_t)(max_ts - ts)) flags |= AVSEEK_FLAG_BACKWARD; 00465 00466 if (url_is_streamed(s->pb)) { 00467 if (stream_index < 0) { 00468 stream_index = av_find_default_stream_index(s); 00469 if (stream_index < 0) 00470 return -1; 00471 00472 /* timestamp for default must be expressed in AV_TIME_BASE units */ 00473 ts = av_rescale_rnd(ts, 1000, AV_TIME_BASE, 00474 flags & AVSEEK_FLAG_BACKWARD ? AV_ROUND_DOWN : AV_ROUND_UP); 00475 } 00476 ret = av_url_read_fseek(s->pb, stream_index, ts, flags); 00477 } 00478 00479 if (ret == AVERROR(ENOSYS)) 00480 ret = av_seek_frame(s, stream_index, ts, flags); 00481 return ret; 00482 } 00483 #endif 00484 00485 AVInputFormat flv_demuxer = { 00486 "flv", 00487 NULL_IF_CONFIG_SMALL("FLV format"), 00488 sizeof(FLVContext), 00489 flv_probe, 00490 flv_read_header, 00491 flv_read_packet, 00492 .read_seek = flv_read_seek, 00493 #if 0 00494 .read_seek2 = flv_read_seek2, 00495 #endif 00496 .extensions = "flv", 00497 .value = CODEC_ID_FLV1, 00498 };