Libav
|
00001 /* 00002 * General DV muxer/demuxer 00003 * Copyright (c) 2003 Roman Shaposhnik 00004 * 00005 * Many thanks to Dan Dennedy <dan@dennedy.org> for providing wealth 00006 * of DV technical info. 00007 * 00008 * Raw DV format 00009 * Copyright (c) 2002 Fabrice Bellard 00010 * 00011 * 50 Mbps (DVCPRO50) and 100 Mbps (DVCPRO HD) support 00012 * Copyright (c) 2006 Daniel Maas <dmaas@maasdigital.com> 00013 * Funded by BBC Research & Development 00014 * 00015 * This file is part of FFmpeg. 00016 * 00017 * FFmpeg is free software; you can redistribute it and/or 00018 * modify it under the terms of the GNU Lesser General Public 00019 * License as published by the Free Software Foundation; either 00020 * version 2.1 of the License, or (at your option) any later version. 00021 * 00022 * FFmpeg is distributed in the hope that it will be useful, 00023 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00024 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00025 * Lesser General Public License for more details. 00026 * 00027 * You should have received a copy of the GNU Lesser General Public 00028 * License along with FFmpeg; if not, write to the Free Software 00029 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00030 */ 00031 #include <time.h> 00032 #include "avformat.h" 00033 #include "libavcodec/dvdata.h" 00034 #include "libavutil/intreadwrite.h" 00035 #include "dv.h" 00036 00037 struct DVDemuxContext { 00038 const DVprofile* sys; /* Current DV profile. E.g.: 525/60, 625/50 */ 00039 AVFormatContext* fctx; 00040 AVStream* vst; 00041 AVStream* ast[4]; 00042 AVPacket audio_pkt[4]; 00043 uint8_t audio_buf[4][8192]; 00044 int ach; 00045 int frames; 00046 uint64_t abytes; 00047 }; 00048 00049 static inline uint16_t dv_audio_12to16(uint16_t sample) 00050 { 00051 uint16_t shift, result; 00052 00053 sample = (sample < 0x800) ? sample : sample | 0xf000; 00054 shift = (sample & 0xf00) >> 8; 00055 00056 if (shift < 0x2 || shift > 0xd) { 00057 result = sample; 00058 } else if (shift < 0x8) { 00059 shift--; 00060 result = (sample - (256 * shift)) << shift; 00061 } else { 00062 shift = 0xe - shift; 00063 result = ((sample + ((256 * shift) + 1)) << shift) - 1; 00064 } 00065 00066 return result; 00067 } 00068 00069 /* 00070 * This is the dumbest implementation of all -- it simply looks at 00071 * a fixed offset and if pack isn't there -- fails. We might want 00072 * to have a fallback mechanism for complete search of missing packs. 00073 */ 00074 static const uint8_t* dv_extract_pack(uint8_t* frame, enum dv_pack_type t) 00075 { 00076 int offs; 00077 00078 switch (t) { 00079 case dv_audio_source: 00080 offs = (80*6 + 80*16*3 + 3); 00081 break; 00082 case dv_audio_control: 00083 offs = (80*6 + 80*16*4 + 3); 00084 break; 00085 case dv_video_control: 00086 offs = (80*5 + 48 + 5); 00087 break; 00088 default: 00089 return NULL; 00090 } 00091 00092 return frame[offs] == t ? &frame[offs] : NULL; 00093 } 00094 00095 /* 00096 * There's a couple of assumptions being made here: 00097 * 1. By default we silence erroneous (0x8000/16bit 0x800/12bit) audio samples. 00098 * We can pass them upwards when ffmpeg will be ready to deal with them. 00099 * 2. We don't do software emphasis. 00100 * 3. Audio is always returned as 16bit linear samples: 12bit nonlinear samples 00101 * are converted into 16bit linear ones. 00102 */ 00103 static int dv_extract_audio(uint8_t* frame, uint8_t* ppcm[4], 00104 const DVprofile *sys) 00105 { 00106 int size, chan, i, j, d, of, smpls, freq, quant, half_ch; 00107 uint16_t lc, rc; 00108 const uint8_t* as_pack; 00109 uint8_t *pcm, ipcm; 00110 00111 as_pack = dv_extract_pack(frame, dv_audio_source); 00112 if (!as_pack) /* No audio ? */ 00113 return 0; 00114 00115 smpls = as_pack[1] & 0x3f; /* samples in this frame - min. samples */ 00116 freq = (as_pack[4] >> 3) & 0x07; /* 0 - 48kHz, 1 - 44,1kHz, 2 - 32kHz */ 00117 quant = as_pack[4] & 0x07; /* 0 - 16bit linear, 1 - 12bit nonlinear */ 00118 00119 if (quant > 1) 00120 return -1; /* unsupported quantization */ 00121 00122 size = (sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */ 00123 half_ch = sys->difseg_size / 2; 00124 00125 /* We work with 720p frames split in half, thus even frames have 00126 * channels 0,1 and odd 2,3. */ 00127 ipcm = (sys->height == 720 && !(frame[1] & 0x0C)) ? 2 : 0; 00128 00129 /* for each DIF channel */ 00130 for (chan = 0; chan < sys->n_difchan; chan++) { 00131 /* next stereo channel (50Mbps and 100Mbps only) */ 00132 pcm = ppcm[ipcm++]; 00133 if (!pcm) 00134 break; 00135 00136 /* for each DIF segment */ 00137 for (i = 0; i < sys->difseg_size; i++) { 00138 frame += 6 * 80; /* skip DIF segment header */ 00139 if (quant == 1 && i == half_ch) { 00140 /* next stereo channel (12bit mode only) */ 00141 pcm = ppcm[ipcm++]; 00142 if (!pcm) 00143 break; 00144 } 00145 00146 /* for each AV sequence */ 00147 for (j = 0; j < 9; j++) { 00148 for (d = 8; d < 80; d += 2) { 00149 if (quant == 0) { /* 16bit quantization */ 00150 of = sys->audio_shuffle[i][j] + (d - 8) / 2 * sys->audio_stride; 00151 if (of*2 >= size) 00152 continue; 00153 00154 pcm[of*2] = frame[d+1]; // FIXME: maybe we have to admit 00155 pcm[of*2+1] = frame[d]; // that DV is a big-endian PCM 00156 if (pcm[of*2+1] == 0x80 && pcm[of*2] == 0x00) 00157 pcm[of*2+1] = 0; 00158 } else { /* 12bit quantization */ 00159 lc = ((uint16_t)frame[d] << 4) | 00160 ((uint16_t)frame[d+2] >> 4); 00161 rc = ((uint16_t)frame[d+1] << 4) | 00162 ((uint16_t)frame[d+2] & 0x0f); 00163 lc = (lc == 0x800 ? 0 : dv_audio_12to16(lc)); 00164 rc = (rc == 0x800 ? 0 : dv_audio_12to16(rc)); 00165 00166 of = sys->audio_shuffle[i%half_ch][j] + (d - 8) / 3 * sys->audio_stride; 00167 if (of*2 >= size) 00168 continue; 00169 00170 pcm[of*2] = lc & 0xff; // FIXME: maybe we have to admit 00171 pcm[of*2+1] = lc >> 8; // that DV is a big-endian PCM 00172 of = sys->audio_shuffle[i%half_ch+half_ch][j] + 00173 (d - 8) / 3 * sys->audio_stride; 00174 pcm[of*2] = rc & 0xff; // FIXME: maybe we have to admit 00175 pcm[of*2+1] = rc >> 8; // that DV is a big-endian PCM 00176 ++d; 00177 } 00178 } 00179 00180 frame += 16 * 80; /* 15 Video DIFs + 1 Audio DIF */ 00181 } 00182 } 00183 } 00184 00185 return size; 00186 } 00187 00188 static int dv_extract_audio_info(DVDemuxContext* c, uint8_t* frame) 00189 { 00190 const uint8_t* as_pack; 00191 int freq, stype, smpls, quant, i, ach; 00192 00193 as_pack = dv_extract_pack(frame, dv_audio_source); 00194 if (!as_pack || !c->sys) { /* No audio ? */ 00195 c->ach = 0; 00196 return 0; 00197 } 00198 00199 smpls = as_pack[1] & 0x3f; /* samples in this frame - min. samples */ 00200 freq = (as_pack[4] >> 3) & 0x07; /* 0 - 48kHz, 1 - 44,1kHz, 2 - 32kHz */ 00201 stype = (as_pack[3] & 0x1f); /* 0 - 2CH, 2 - 4CH, 3 - 8CH */ 00202 quant = as_pack[4] & 0x07; /* 0 - 16bit linear, 1 - 12bit nonlinear */ 00203 00204 if (stype > 3) { 00205 av_log(c->fctx, AV_LOG_ERROR, "stype %d is invalid\n", stype); 00206 c->ach = 0; 00207 return 0; 00208 } 00209 00210 /* note: ach counts PAIRS of channels (i.e. stereo channels) */ 00211 ach = ((int[4]){ 1, 0, 2, 4})[stype]; 00212 if (ach == 1 && quant && freq == 2) 00213 ach = 2; 00214 00215 /* Dynamic handling of the audio streams in DV */ 00216 for (i = 0; i < ach; i++) { 00217 if (!c->ast[i]) { 00218 c->ast[i] = av_new_stream(c->fctx, 0); 00219 if (!c->ast[i]) 00220 break; 00221 av_set_pts_info(c->ast[i], 64, 1, 30000); 00222 c->ast[i]->codec->codec_type = AVMEDIA_TYPE_AUDIO; 00223 c->ast[i]->codec->codec_id = CODEC_ID_PCM_S16LE; 00224 00225 av_init_packet(&c->audio_pkt[i]); 00226 c->audio_pkt[i].size = 0; 00227 c->audio_pkt[i].data = c->audio_buf[i]; 00228 c->audio_pkt[i].stream_index = c->ast[i]->index; 00229 c->audio_pkt[i].flags |= AV_PKT_FLAG_KEY; 00230 } 00231 c->ast[i]->codec->sample_rate = dv_audio_frequency[freq]; 00232 c->ast[i]->codec->channels = 2; 00233 c->ast[i]->codec->bit_rate = 2 * dv_audio_frequency[freq] * 16; 00234 c->ast[i]->start_time = 0; 00235 } 00236 c->ach = i; 00237 00238 return (c->sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */; 00239 } 00240 00241 static int dv_extract_video_info(DVDemuxContext *c, uint8_t* frame) 00242 { 00243 const uint8_t* vsc_pack; 00244 AVCodecContext* avctx; 00245 int apt, is16_9; 00246 int size = 0; 00247 00248 if (c->sys) { 00249 avctx = c->vst->codec; 00250 00251 av_set_pts_info(c->vst, 64, c->sys->time_base.num, 00252 c->sys->time_base.den); 00253 avctx->time_base= c->sys->time_base; 00254 if (!avctx->width){ 00255 avctx->width = c->sys->width; 00256 avctx->height = c->sys->height; 00257 } 00258 avctx->pix_fmt = c->sys->pix_fmt; 00259 00260 /* finding out SAR is a little bit messy */ 00261 vsc_pack = dv_extract_pack(frame, dv_video_control); 00262 apt = frame[4] & 0x07; 00263 is16_9 = (vsc_pack && ((vsc_pack[2] & 0x07) == 0x02 || 00264 (!apt && (vsc_pack[2] & 0x07) == 0x07))); 00265 c->vst->sample_aspect_ratio = c->sys->sar[is16_9]; 00266 avctx->bit_rate = av_rescale_q(c->sys->frame_size, (AVRational){8,1}, 00267 c->sys->time_base); 00268 size = c->sys->frame_size; 00269 } 00270 return size; 00271 } 00272 00273 /* 00274 * The following 3 functions constitute our interface to the world 00275 */ 00276 00277 DVDemuxContext* dv_init_demux(AVFormatContext *s) 00278 { 00279 DVDemuxContext *c; 00280 00281 c = av_mallocz(sizeof(DVDemuxContext)); 00282 if (!c) 00283 return NULL; 00284 00285 c->vst = av_new_stream(s, 0); 00286 if (!c->vst) { 00287 av_free(c); 00288 return NULL; 00289 } 00290 00291 c->sys = NULL; 00292 c->fctx = s; 00293 memset(c->ast, 0, sizeof(c->ast)); 00294 c->ach = 0; 00295 c->frames = 0; 00296 c->abytes = 0; 00297 00298 c->vst->codec->codec_type = AVMEDIA_TYPE_VIDEO; 00299 c->vst->codec->codec_id = CODEC_ID_DVVIDEO; 00300 c->vst->codec->bit_rate = 25000000; 00301 c->vst->start_time = 0; 00302 00303 return c; 00304 } 00305 00306 int dv_get_packet(DVDemuxContext *c, AVPacket *pkt) 00307 { 00308 int size = -1; 00309 int i; 00310 00311 for (i = 0; i < c->ach; i++) { 00312 if (c->ast[i] && c->audio_pkt[i].size) { 00313 *pkt = c->audio_pkt[i]; 00314 c->audio_pkt[i].size = 0; 00315 size = pkt->size; 00316 break; 00317 } 00318 } 00319 00320 return size; 00321 } 00322 00323 int dv_produce_packet(DVDemuxContext *c, AVPacket *pkt, 00324 uint8_t* buf, int buf_size) 00325 { 00326 int size, i; 00327 uint8_t *ppcm[4] = {0}; 00328 00329 if (buf_size < DV_PROFILE_BYTES || 00330 !(c->sys = ff_dv_frame_profile(c->sys, buf, buf_size)) || 00331 buf_size < c->sys->frame_size) { 00332 return -1; /* Broken frame, or not enough data */ 00333 } 00334 00335 /* Queueing audio packet */ 00336 /* FIXME: in case of no audio/bad audio we have to do something */ 00337 size = dv_extract_audio_info(c, buf); 00338 for (i = 0; i < c->ach; i++) { 00339 c->audio_pkt[i].size = size; 00340 c->audio_pkt[i].pts = c->abytes * 30000*8 / c->ast[i]->codec->bit_rate; 00341 ppcm[i] = c->audio_buf[i]; 00342 } 00343 if (c->ach) 00344 dv_extract_audio(buf, ppcm, c->sys); 00345 00346 /* We work with 720p frames split in half, thus even frames have 00347 * channels 0,1 and odd 2,3. */ 00348 if (c->sys->height == 720) { 00349 if (buf[1] & 0x0C) { 00350 c->audio_pkt[2].size = c->audio_pkt[3].size = 0; 00351 } else { 00352 c->audio_pkt[0].size = c->audio_pkt[1].size = 0; 00353 c->abytes += size; 00354 } 00355 } else { 00356 c->abytes += size; 00357 } 00358 00359 /* Now it's time to return video packet */ 00360 size = dv_extract_video_info(c, buf); 00361 av_init_packet(pkt); 00362 pkt->data = buf; 00363 pkt->size = size; 00364 pkt->flags |= AV_PKT_FLAG_KEY; 00365 pkt->stream_index = c->vst->id; 00366 pkt->pts = c->frames; 00367 00368 c->frames++; 00369 00370 return size; 00371 } 00372 00373 static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c, 00374 int64_t timestamp, int flags) 00375 { 00376 // FIXME: sys may be wrong if last dv_read_packet() failed (buffer is junk) 00377 const DVprofile* sys = ff_dv_codec_profile(c->vst->codec); 00378 int64_t offset; 00379 int64_t size = url_fsize(s->pb); 00380 int64_t max_offset = ((size-1) / sys->frame_size) * sys->frame_size; 00381 00382 offset = sys->frame_size * timestamp; 00383 00384 if (size >= 0 && offset > max_offset) offset = max_offset; 00385 else if (offset < 0) offset = 0; 00386 00387 return offset; 00388 } 00389 00390 void dv_offset_reset(DVDemuxContext *c, int64_t frame_offset) 00391 { 00392 c->frames= frame_offset; 00393 if (c->ach) 00394 c->abytes= av_rescale_q(c->frames, c->sys->time_base, 00395 (AVRational){8, c->ast[0]->codec->bit_rate}); 00396 c->audio_pkt[0].size = c->audio_pkt[1].size = 0; 00397 c->audio_pkt[2].size = c->audio_pkt[3].size = 0; 00398 } 00399 00400 /************************************************************ 00401 * Implementation of the easiest DV storage of all -- raw DV. 00402 ************************************************************/ 00403 00404 typedef struct RawDVContext { 00405 DVDemuxContext* dv_demux; 00406 uint8_t buf[DV_MAX_FRAME_SIZE]; 00407 } RawDVContext; 00408 00409 static int dv_read_header(AVFormatContext *s, 00410 AVFormatParameters *ap) 00411 { 00412 unsigned state, marker_pos = 0; 00413 RawDVContext *c = s->priv_data; 00414 00415 c->dv_demux = dv_init_demux(s); 00416 if (!c->dv_demux) 00417 return -1; 00418 00419 state = get_be32(s->pb); 00420 while ((state & 0xffffff7f) != 0x1f07003f) { 00421 if (url_feof(s->pb)) { 00422 av_log(s, AV_LOG_ERROR, "Cannot find DV header.\n"); 00423 return -1; 00424 } 00425 if (state == 0x003f0700 || state == 0xff3f0700) 00426 marker_pos = url_ftell(s->pb); 00427 if (state == 0xff3f0701 && url_ftell(s->pb) - marker_pos == 80) { 00428 url_fseek(s->pb, -163, SEEK_CUR); 00429 state = get_be32(s->pb); 00430 break; 00431 } 00432 state = (state << 8) | get_byte(s->pb); 00433 } 00434 AV_WB32(c->buf, state); 00435 00436 if (get_buffer(s->pb, c->buf + 4, DV_PROFILE_BYTES - 4) <= 0 || 00437 url_fseek(s->pb, -DV_PROFILE_BYTES, SEEK_CUR) < 0) 00438 return AVERROR(EIO); 00439 00440 c->dv_demux->sys = ff_dv_frame_profile(c->dv_demux->sys, c->buf, DV_PROFILE_BYTES); 00441 if (!c->dv_demux->sys) { 00442 av_log(s, AV_LOG_ERROR, "Can't determine profile of DV input stream.\n"); 00443 return -1; 00444 } 00445 00446 s->bit_rate = av_rescale_q(c->dv_demux->sys->frame_size, (AVRational){8,1}, 00447 c->dv_demux->sys->time_base); 00448 00449 return 0; 00450 } 00451 00452 00453 static int dv_read_packet(AVFormatContext *s, AVPacket *pkt) 00454 { 00455 int size; 00456 RawDVContext *c = s->priv_data; 00457 00458 size = dv_get_packet(c->dv_demux, pkt); 00459 00460 if (size < 0) { 00461 if (!c->dv_demux->sys) 00462 return AVERROR(EIO); 00463 size = c->dv_demux->sys->frame_size; 00464 if (get_buffer(s->pb, c->buf, size) <= 0) 00465 return AVERROR(EIO); 00466 00467 size = dv_produce_packet(c->dv_demux, pkt, c->buf, size); 00468 } 00469 00470 return size; 00471 } 00472 00473 static int dv_read_seek(AVFormatContext *s, int stream_index, 00474 int64_t timestamp, int flags) 00475 { 00476 RawDVContext *r = s->priv_data; 00477 DVDemuxContext *c = r->dv_demux; 00478 int64_t offset = dv_frame_offset(s, c, timestamp, flags); 00479 00480 dv_offset_reset(c, offset / c->sys->frame_size); 00481 00482 offset = url_fseek(s->pb, offset, SEEK_SET); 00483 return (offset < 0) ? offset : 0; 00484 } 00485 00486 static int dv_read_close(AVFormatContext *s) 00487 { 00488 RawDVContext *c = s->priv_data; 00489 av_free(c->dv_demux); 00490 return 0; 00491 } 00492 00493 static int dv_probe(AVProbeData *p) 00494 { 00495 unsigned state, marker_pos = 0; 00496 int i; 00497 int matches = 0; 00498 int secondary_matches = 0; 00499 00500 if (p->buf_size < 5) 00501 return 0; 00502 00503 state = AV_RB32(p->buf); 00504 for (i = 4; i < p->buf_size; i++) { 00505 if ((state & 0xffffff7f) == 0x1f07003f) 00506 matches++; 00507 // any section header, also with seq/chan num != 0, 00508 // should appear around every 12000 bytes, at least 10 per frame 00509 if ((state & 0xff07ff7f) == 0x1f07003f) 00510 secondary_matches++; 00511 if (state == 0x003f0700 || state == 0xff3f0700) 00512 marker_pos = i; 00513 if (state == 0xff3f0701 && i - marker_pos == 80) 00514 matches++; 00515 state = (state << 8) | p->buf[i]; 00516 } 00517 00518 if (matches && p->buf_size / matches < 1024*1024) { 00519 if (matches > 4 || (secondary_matches >= 10 && p->buf_size / secondary_matches < 24000)) 00520 return AVPROBE_SCORE_MAX*3/4; // not max to avoid dv in mov to match 00521 return AVPROBE_SCORE_MAX/4; 00522 } 00523 return 0; 00524 } 00525 00526 #if CONFIG_DV_DEMUXER 00527 AVInputFormat dv_demuxer = { 00528 "dv", 00529 NULL_IF_CONFIG_SMALL("DV video format"), 00530 sizeof(RawDVContext), 00531 dv_probe, 00532 dv_read_header, 00533 dv_read_packet, 00534 dv_read_close, 00535 dv_read_seek, 00536 .extensions = "dv,dif", 00537 }; 00538 #endif