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libavformat/dv.c

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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     if (freq >= FF_ARRAY_ELEMS(dv_audio_frequency))
00123         return AVERROR_INVALIDDATA;
00124 
00125     size = (sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */
00126     half_ch = sys->difseg_size / 2;
00127 
00128     /* We work with 720p frames split in half, thus even frames have
00129      * channels 0,1 and odd 2,3. */
00130     ipcm = (sys->height == 720 && !(frame[1] & 0x0C)) ? 2 : 0;
00131 
00132     /* for each DIF channel */
00133     for (chan = 0; chan < sys->n_difchan; chan++) {
00134         /* next stereo channel (50Mbps and 100Mbps only) */
00135         pcm = ppcm[ipcm++];
00136         if (!pcm)
00137             break;
00138 
00139         /* for each DIF segment */
00140         for (i = 0; i < sys->difseg_size; i++) {
00141             frame += 6 * 80; /* skip DIF segment header */
00142             if (quant == 1 && i == half_ch) {
00143                 /* next stereo channel (12bit mode only) */
00144                 pcm = ppcm[ipcm++];
00145                 if (!pcm)
00146                     break;
00147             }
00148 
00149             /* for each AV sequence */
00150             for (j = 0; j < 9; j++) {
00151                 for (d = 8; d < 80; d += 2) {
00152                     if (quant == 0) {  /* 16bit quantization */
00153                         of = sys->audio_shuffle[i][j] + (d - 8) / 2 * sys->audio_stride;
00154                         if (of*2 >= size)
00155                             continue;
00156 
00157                         pcm[of*2]   = frame[d+1]; // FIXME: maybe we have to admit
00158                         pcm[of*2+1] = frame[d];   //        that DV is a big-endian PCM
00159                         if (pcm[of*2+1] == 0x80 && pcm[of*2] == 0x00)
00160                             pcm[of*2+1] = 0;
00161                     } else {           /* 12bit quantization */
00162                         lc = ((uint16_t)frame[d]   << 4) |
00163                              ((uint16_t)frame[d+2] >> 4);
00164                         rc = ((uint16_t)frame[d+1] << 4) |
00165                              ((uint16_t)frame[d+2] & 0x0f);
00166                         lc = (lc == 0x800 ? 0 : dv_audio_12to16(lc));
00167                         rc = (rc == 0x800 ? 0 : dv_audio_12to16(rc));
00168 
00169                         of = sys->audio_shuffle[i%half_ch][j] + (d - 8) / 3 * sys->audio_stride;
00170                         if (of*2 >= size)
00171                             continue;
00172 
00173                         pcm[of*2]   = lc & 0xff; // FIXME: maybe we have to admit
00174                         pcm[of*2+1] = lc >> 8;   //        that DV is a big-endian PCM
00175                         of = sys->audio_shuffle[i%half_ch+half_ch][j] +
00176                             (d - 8) / 3 * sys->audio_stride;
00177                         pcm[of*2]   = rc & 0xff; // FIXME: maybe we have to admit
00178                         pcm[of*2+1] = rc >> 8;   //        that DV is a big-endian PCM
00179                         ++d;
00180                     }
00181                 }
00182 
00183                 frame += 16 * 80; /* 15 Video DIFs + 1 Audio DIF */
00184             }
00185         }
00186     }
00187 
00188     return size;
00189 }
00190 
00191 static int dv_extract_audio_info(DVDemuxContext* c, uint8_t* frame)
00192 {
00193     const uint8_t* as_pack;
00194     int freq, stype, smpls, quant, i, ach;
00195 
00196     as_pack = dv_extract_pack(frame, dv_audio_source);
00197     if (!as_pack || !c->sys) {    /* No audio ? */
00198         c->ach = 0;
00199         return 0;
00200     }
00201 
00202     smpls =  as_pack[1] & 0x3f;       /* samples in this frame - min. samples */
00203     freq  = (as_pack[4] >> 3) & 0x07; /* 0 - 48kHz, 1 - 44,1kHz, 2 - 32kHz */
00204     stype = (as_pack[3] & 0x1f);      /* 0 - 2CH, 2 - 4CH, 3 - 8CH */
00205     quant =  as_pack[4] & 0x07;       /* 0 - 16bit linear, 1 - 12bit nonlinear */
00206 
00207     if (freq >= FF_ARRAY_ELEMS(dv_audio_frequency)) {
00208         av_log(c->fctx, AV_LOG_ERROR,
00209                "Unrecognized audio sample rate index (%d)\n", freq);
00210         return 0;
00211     }
00212 
00213     if (stype > 3) {
00214         av_log(c->fctx, AV_LOG_ERROR, "stype %d is invalid\n", stype);
00215         c->ach = 0;
00216         return 0;
00217     }
00218 
00219     /* note: ach counts PAIRS of channels (i.e. stereo channels) */
00220     ach = ((int[4]){  1,  0,  2,  4})[stype];
00221     if (ach == 1 && quant && freq == 2)
00222         ach = 2;
00223 
00224     /* Dynamic handling of the audio streams in DV */
00225     for (i = 0; i < ach; i++) {
00226        if (!c->ast[i]) {
00227            c->ast[i] = av_new_stream(c->fctx, 0);
00228            if (!c->ast[i])
00229                break;
00230            av_set_pts_info(c->ast[i], 64, 1, 30000);
00231            c->ast[i]->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00232            c->ast[i]->codec->codec_id   = CODEC_ID_PCM_S16LE;
00233 
00234            av_init_packet(&c->audio_pkt[i]);
00235            c->audio_pkt[i].size         = 0;
00236            c->audio_pkt[i].data         = c->audio_buf[i];
00237            c->audio_pkt[i].stream_index = c->ast[i]->index;
00238            c->audio_pkt[i].flags       |= AV_PKT_FLAG_KEY;
00239        }
00240        c->ast[i]->codec->sample_rate = dv_audio_frequency[freq];
00241        c->ast[i]->codec->channels    = 2;
00242        c->ast[i]->codec->bit_rate    = 2 * dv_audio_frequency[freq] * 16;
00243        c->ast[i]->start_time         = 0;
00244     }
00245     c->ach = i;
00246 
00247     return (c->sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */;
00248 }
00249 
00250 static int dv_extract_video_info(DVDemuxContext *c, uint8_t* frame)
00251 {
00252     const uint8_t* vsc_pack;
00253     AVCodecContext* avctx;
00254     int apt, is16_9;
00255     int size = 0;
00256 
00257     if (c->sys) {
00258         avctx = c->vst->codec;
00259 
00260         av_set_pts_info(c->vst, 64, c->sys->time_base.num,
00261                         c->sys->time_base.den);
00262         avctx->time_base= c->sys->time_base;
00263         if (!avctx->width){
00264             avctx->width = c->sys->width;
00265             avctx->height = c->sys->height;
00266         }
00267         avctx->pix_fmt = c->sys->pix_fmt;
00268 
00269         /* finding out SAR is a little bit messy */
00270         vsc_pack = dv_extract_pack(frame, dv_video_control);
00271         apt      = frame[4] & 0x07;
00272         is16_9   = (vsc_pack && ((vsc_pack[2] & 0x07) == 0x02 ||
00273                                 (!apt && (vsc_pack[2] & 0x07) == 0x07)));
00274         c->vst->sample_aspect_ratio = c->sys->sar[is16_9];
00275         avctx->bit_rate = av_rescale_q(c->sys->frame_size, (AVRational){8,1},
00276                                        c->sys->time_base);
00277         size = c->sys->frame_size;
00278     }
00279     return size;
00280 }
00281 
00282 /*
00283  * The following 3 functions constitute our interface to the world
00284  */
00285 
00286 DVDemuxContext* dv_init_demux(AVFormatContext *s)
00287 {
00288     DVDemuxContext *c;
00289 
00290     c = av_mallocz(sizeof(DVDemuxContext));
00291     if (!c)
00292         return NULL;
00293 
00294     c->vst = av_new_stream(s, 0);
00295     if (!c->vst) {
00296         av_free(c);
00297         return NULL;
00298     }
00299 
00300     c->sys  = NULL;
00301     c->fctx = s;
00302     memset(c->ast, 0, sizeof(c->ast));
00303     c->ach    = 0;
00304     c->frames = 0;
00305     c->abytes = 0;
00306 
00307     c->vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00308     c->vst->codec->codec_id   = CODEC_ID_DVVIDEO;
00309     c->vst->codec->bit_rate   = 25000000;
00310     c->vst->start_time        = 0;
00311 
00312     return c;
00313 }
00314 
00315 int dv_get_packet(DVDemuxContext *c, AVPacket *pkt)
00316 {
00317     int size = -1;
00318     int i;
00319 
00320     for (i = 0; i < c->ach; i++) {
00321        if (c->ast[i] && c->audio_pkt[i].size) {
00322            *pkt = c->audio_pkt[i];
00323            c->audio_pkt[i].size = 0;
00324            size = pkt->size;
00325            break;
00326        }
00327     }
00328 
00329     return size;
00330 }
00331 
00332 int dv_produce_packet(DVDemuxContext *c, AVPacket *pkt,
00333                       uint8_t* buf, int buf_size, int64_t pos)
00334 {
00335     int size, i;
00336     uint8_t *ppcm[4] = {0};
00337 
00338     if (buf_size < DV_PROFILE_BYTES ||
00339         !(c->sys = ff_dv_frame_profile(c->sys, buf, buf_size)) ||
00340         buf_size < c->sys->frame_size) {
00341           return -1;   /* Broken frame, or not enough data */
00342     }
00343 
00344     /* Queueing audio packet */
00345     /* FIXME: in case of no audio/bad audio we have to do something */
00346     size = dv_extract_audio_info(c, buf);
00347     for (i = 0; i < c->ach; i++) {
00348        c->audio_pkt[i].pos  = pos;
00349        c->audio_pkt[i].size = size;
00350        c->audio_pkt[i].pts  = c->abytes * 30000*8 / c->ast[i]->codec->bit_rate;
00351        ppcm[i] = c->audio_buf[i];
00352     }
00353     if (c->ach)
00354         dv_extract_audio(buf, ppcm, c->sys);
00355 
00356     /* We work with 720p frames split in half, thus even frames have
00357      * channels 0,1 and odd 2,3. */
00358     if (c->sys->height == 720) {
00359         if (buf[1] & 0x0C) {
00360             c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
00361         } else {
00362             c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
00363             c->abytes += size;
00364         }
00365     } else {
00366         c->abytes += size;
00367     }
00368 
00369     /* Now it's time to return video packet */
00370     size = dv_extract_video_info(c, buf);
00371     av_init_packet(pkt);
00372     pkt->data         = buf;
00373     pkt->pos          = pos;
00374     pkt->size         = size;
00375     pkt->flags       |= AV_PKT_FLAG_KEY;
00376     pkt->stream_index = c->vst->id;
00377     pkt->pts          = c->frames;
00378 
00379     c->frames++;
00380 
00381     return size;
00382 }
00383 
00384 static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c,
00385                               int64_t timestamp, int flags)
00386 {
00387     // FIXME: sys may be wrong if last dv_read_packet() failed (buffer is junk)
00388     const DVprofile* sys = ff_dv_codec_profile(c->vst->codec);
00389     int64_t offset;
00390     int64_t size = avio_size(s->pb) - s->data_offset;
00391     int64_t max_offset = ((size-1) / sys->frame_size) * sys->frame_size;
00392 
00393     offset = sys->frame_size * timestamp;
00394 
00395     if (size >= 0 && offset > max_offset) offset = max_offset;
00396     else if (offset < 0) offset = 0;
00397 
00398     return offset + s->data_offset;
00399 }
00400 
00401 void dv_offset_reset(DVDemuxContext *c, int64_t frame_offset)
00402 {
00403     c->frames= frame_offset;
00404     if (c->ach)
00405         c->abytes= av_rescale_q(c->frames, c->sys->time_base,
00406                                 (AVRational){8, c->ast[0]->codec->bit_rate});
00407     c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
00408     c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
00409 }
00410 
00411 /************************************************************
00412  * Implementation of the easiest DV storage of all -- raw DV.
00413  ************************************************************/
00414 
00415 typedef struct RawDVContext {
00416     DVDemuxContext* dv_demux;
00417     uint8_t         buf[DV_MAX_FRAME_SIZE];
00418 } RawDVContext;
00419 
00420 static int dv_read_header(AVFormatContext *s,
00421                           AVFormatParameters *ap)
00422 {
00423     unsigned state, marker_pos = 0;
00424     RawDVContext *c = s->priv_data;
00425 
00426     c->dv_demux = dv_init_demux(s);
00427     if (!c->dv_demux)
00428         return -1;
00429 
00430     state = avio_rb32(s->pb);
00431     while ((state & 0xffffff7f) != 0x1f07003f) {
00432         if (url_feof(s->pb)) {
00433             av_log(s, AV_LOG_ERROR, "Cannot find DV header.\n");
00434             return -1;
00435         }
00436         if (state == 0x003f0700 || state == 0xff3f0700)
00437             marker_pos = avio_tell(s->pb);
00438         if (state == 0xff3f0701 && avio_tell(s->pb) - marker_pos == 80) {
00439             avio_seek(s->pb, -163, SEEK_CUR);
00440             state = avio_rb32(s->pb);
00441             break;
00442         }
00443         state = (state << 8) | avio_r8(s->pb);
00444     }
00445     AV_WB32(c->buf, state);
00446 
00447     if (avio_read(s->pb, c->buf + 4, DV_PROFILE_BYTES - 4) <= 0 ||
00448         avio_seek(s->pb, -DV_PROFILE_BYTES, SEEK_CUR) < 0)
00449         return AVERROR(EIO);
00450 
00451     c->dv_demux->sys = ff_dv_frame_profile(c->dv_demux->sys, c->buf, DV_PROFILE_BYTES);
00452     if (!c->dv_demux->sys) {
00453         av_log(s, AV_LOG_ERROR, "Can't determine profile of DV input stream.\n");
00454         return -1;
00455     }
00456 
00457     s->bit_rate = av_rescale_q(c->dv_demux->sys->frame_size, (AVRational){8,1},
00458                                c->dv_demux->sys->time_base);
00459 
00460     return 0;
00461 }
00462 
00463 
00464 static int dv_read_packet(AVFormatContext *s, AVPacket *pkt)
00465 {
00466     int size;
00467     RawDVContext *c = s->priv_data;
00468 
00469     size = dv_get_packet(c->dv_demux, pkt);
00470 
00471     if (size < 0) {
00472         int64_t pos = avio_tell(s->pb);
00473         if (!c->dv_demux->sys)
00474             return AVERROR(EIO);
00475         size = c->dv_demux->sys->frame_size;
00476         if (avio_read(s->pb, c->buf, size) <= 0)
00477             return AVERROR(EIO);
00478 
00479         size = dv_produce_packet(c->dv_demux, pkt, c->buf, size, pos);
00480     }
00481 
00482     return size;
00483 }
00484 
00485 static int dv_read_seek(AVFormatContext *s, int stream_index,
00486                        int64_t timestamp, int flags)
00487 {
00488     RawDVContext *r   = s->priv_data;
00489     DVDemuxContext *c = r->dv_demux;
00490     int64_t offset    = dv_frame_offset(s, c, timestamp, flags);
00491 
00492     dv_offset_reset(c, offset / c->sys->frame_size);
00493 
00494     offset = avio_seek(s->pb, offset, SEEK_SET);
00495     return (offset < 0) ? offset : 0;
00496 }
00497 
00498 static int dv_read_close(AVFormatContext *s)
00499 {
00500     RawDVContext *c = s->priv_data;
00501     av_free(c->dv_demux);
00502     return 0;
00503 }
00504 
00505 static int dv_probe(AVProbeData *p)
00506 {
00507     unsigned state, marker_pos = 0;
00508     int i;
00509     int matches = 0;
00510     int secondary_matches = 0;
00511 
00512     if (p->buf_size < 5)
00513         return 0;
00514 
00515     state = AV_RB32(p->buf);
00516     for (i = 4; i < p->buf_size; i++) {
00517         if ((state & 0xffffff7f) == 0x1f07003f)
00518             matches++;
00519         // any section header, also with seq/chan num != 0,
00520         // should appear around every 12000 bytes, at least 10 per frame
00521         if ((state & 0xff07ff7f) == 0x1f07003f)
00522             secondary_matches++;
00523         if (state == 0x003f0700 || state == 0xff3f0700)
00524             marker_pos = i;
00525         if (state == 0xff3f0701 && i - marker_pos == 80)
00526             matches++;
00527         state = (state << 8) | p->buf[i];
00528     }
00529 
00530     if (matches && p->buf_size / matches < 1024*1024) {
00531         if (matches > 4 || (secondary_matches >= 10 && p->buf_size / secondary_matches < 24000))
00532             return AVPROBE_SCORE_MAX*3/4; // not max to avoid dv in mov to match
00533         return AVPROBE_SCORE_MAX/4;
00534     }
00535     return 0;
00536 }
00537 
00538 #if CONFIG_DV_DEMUXER
00539 AVInputFormat ff_dv_demuxer = {
00540     "dv",
00541     NULL_IF_CONFIG_SMALL("DV video format"),
00542     sizeof(RawDVContext),
00543     dv_probe,
00544     dv_read_header,
00545     dv_read_packet,
00546     dv_read_close,
00547     dv_read_seek,
00548     .extensions = "dv,dif",
00549 };
00550 #endif

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