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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 Libav.
00016  *
00017  * Libav 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  * Libav 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 Libav; 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 "internal.h"
00034 #include "libavcodec/dvdata.h"
00035 #include "libavutil/intreadwrite.h"
00036 #include "libavutil/mathematics.h"
00037 #include "dv.h"
00038 
00039 struct DVDemuxContext {
00040     const DVprofile*  sys;    /* Current DV profile. E.g.: 525/60, 625/50 */
00041     AVFormatContext*  fctx;
00042     AVStream*         vst;
00043     AVStream*         ast[4];
00044     AVPacket          audio_pkt[4];
00045     uint8_t           audio_buf[4][8192];
00046     int               ach;
00047     int               frames;
00048     uint64_t          abytes;
00049 };
00050 
00051 static inline uint16_t dv_audio_12to16(uint16_t sample)
00052 {
00053     uint16_t shift, result;
00054 
00055     sample = (sample < 0x800) ? sample : sample | 0xf000;
00056     shift  = (sample & 0xf00) >> 8;
00057 
00058     if (shift < 0x2 || shift > 0xd) {
00059         result = sample;
00060     } else if (shift < 0x8) {
00061         shift--;
00062         result = (sample - (256 * shift)) << shift;
00063     } else {
00064         shift = 0xe - shift;
00065         result = ((sample + ((256 * shift) + 1)) << shift) - 1;
00066     }
00067 
00068     return result;
00069 }
00070 
00071 /*
00072  * This is the dumbest implementation of all -- it simply looks at
00073  * a fixed offset and if pack isn't there -- fails. We might want
00074  * to have a fallback mechanism for complete search of missing packs.
00075  */
00076 static const uint8_t* dv_extract_pack(uint8_t* frame, enum dv_pack_type t)
00077 {
00078     int offs;
00079 
00080     switch (t) {
00081     case dv_audio_source:
00082         offs = (80*6 + 80*16*3 + 3);
00083         break;
00084     case dv_audio_control:
00085         offs = (80*6 + 80*16*4 + 3);
00086         break;
00087     case dv_video_control:
00088         offs = (80*5 + 48 + 5);
00089         break;
00090     default:
00091         return NULL;
00092     }
00093 
00094     return frame[offs] == t ? &frame[offs] : NULL;
00095 }
00096 
00097 /*
00098  * There's a couple of assumptions being made here:
00099  * 1. By default we silence erroneous (0x8000/16bit 0x800/12bit) audio samples.
00100  *    We can pass them upwards when libavcodec will be ready to deal with them.
00101  * 2. We don't do software emphasis.
00102  * 3. Audio is always returned as 16bit linear samples: 12bit nonlinear samples
00103  *    are converted into 16bit linear ones.
00104  */
00105 static int dv_extract_audio(uint8_t* frame, uint8_t* ppcm[4],
00106                             const DVprofile *sys)
00107 {
00108     int size, chan, i, j, d, of, smpls, freq, quant, half_ch;
00109     uint16_t lc, rc;
00110     const uint8_t* as_pack;
00111     uint8_t *pcm, ipcm;
00112 
00113     as_pack = dv_extract_pack(frame, dv_audio_source);
00114     if (!as_pack)    /* No audio ? */
00115         return 0;
00116 
00117     smpls =  as_pack[1] & 0x3f;       /* samples in this frame - min. samples */
00118     freq  = (as_pack[4] >> 3) & 0x07; /* 0 - 48kHz, 1 - 44,1kHz, 2 - 32kHz */
00119     quant =  as_pack[4] & 0x07;       /* 0 - 16bit linear, 1 - 12bit nonlinear */
00120 
00121     if (quant > 1)
00122         return -1; /* unsupported quantization */
00123 
00124     size = (sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */
00125     half_ch = sys->difseg_size / 2;
00126 
00127     /* We work with 720p frames split in half, thus even frames have
00128      * channels 0,1 and odd 2,3. */
00129     ipcm = (sys->height == 720 && !(frame[1] & 0x0C)) ? 2 : 0;
00130     pcm  = ppcm[ipcm++];
00131 
00132     /* for each DIF channel */
00133     for (chan = 0; chan < sys->n_difchan; chan++) {
00134         /* for each DIF segment */
00135         for (i = 0; i < sys->difseg_size; i++) {
00136             frame += 6 * 80; /* skip DIF segment header */
00137             if (quant == 1 && i == half_ch) {
00138                 /* next stereo channel (12bit mode only) */
00139                 pcm = ppcm[ipcm++];
00140                 if (!pcm)
00141                     break;
00142             }
00143 
00144             /* for each AV sequence */
00145             for (j = 0; j < 9; j++) {
00146                 for (d = 8; d < 80; d += 2) {
00147                     if (quant == 0) {  /* 16bit quantization */
00148                         of = sys->audio_shuffle[i][j] + (d - 8) / 2 * sys->audio_stride;
00149                         if (of*2 >= size)
00150                             continue;
00151 
00152                         pcm[of*2]   = frame[d+1]; // FIXME: maybe we have to admit
00153                         pcm[of*2+1] = frame[d];   //        that DV is a big-endian PCM
00154                         if (pcm[of*2+1] == 0x80 && pcm[of*2] == 0x00)
00155                             pcm[of*2+1] = 0;
00156                     } else {           /* 12bit quantization */
00157                         lc = ((uint16_t)frame[d]   << 4) |
00158                              ((uint16_t)frame[d+2] >> 4);
00159                         rc = ((uint16_t)frame[d+1] << 4) |
00160                              ((uint16_t)frame[d+2] & 0x0f);
00161                         lc = (lc == 0x800 ? 0 : dv_audio_12to16(lc));
00162                         rc = (rc == 0x800 ? 0 : dv_audio_12to16(rc));
00163 
00164                         of = sys->audio_shuffle[i%half_ch][j] + (d - 8) / 3 * sys->audio_stride;
00165                         if (of*2 >= size)
00166                             continue;
00167 
00168                         pcm[of*2]   = lc & 0xff; // FIXME: maybe we have to admit
00169                         pcm[of*2+1] = lc >> 8;   //        that DV is a big-endian PCM
00170                         of = sys->audio_shuffle[i%half_ch+half_ch][j] +
00171                             (d - 8) / 3 * sys->audio_stride;
00172                         pcm[of*2]   = rc & 0xff; // FIXME: maybe we have to admit
00173                         pcm[of*2+1] = rc >> 8;   //        that DV is a big-endian PCM
00174                         ++d;
00175                     }
00176                 }
00177 
00178                 frame += 16 * 80; /* 15 Video DIFs + 1 Audio DIF */
00179             }
00180         }
00181 
00182         /* next stereo channel (50Mbps and 100Mbps only) */
00183         pcm = ppcm[ipcm++];
00184         if (!pcm)
00185             break;
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     /* note: ach counts PAIRS of channels (i.e. stereo channels) */
00208     ach = ((int[4]){  1,  0,  2,  4})[stype];
00209     if (ach == 1 && quant && freq == 2)
00210         ach = 2;
00211 
00212     /* Dynamic handling of the audio streams in DV */
00213     for (i = 0; i < ach; i++) {
00214        if (!c->ast[i]) {
00215            c->ast[i] = avformat_new_stream(c->fctx, NULL);
00216            if (!c->ast[i])
00217                break;
00218            avpriv_set_pts_info(c->ast[i], 64, 1, 30000);
00219            c->ast[i]->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00220            c->ast[i]->codec->codec_id   = CODEC_ID_PCM_S16LE;
00221 
00222            av_init_packet(&c->audio_pkt[i]);
00223            c->audio_pkt[i].size         = 0;
00224            c->audio_pkt[i].data         = c->audio_buf[i];
00225            c->audio_pkt[i].stream_index = c->ast[i]->index;
00226            c->audio_pkt[i].flags       |= AV_PKT_FLAG_KEY;
00227        }
00228        c->ast[i]->codec->sample_rate = dv_audio_frequency[freq];
00229        c->ast[i]->codec->channels    = 2;
00230        c->ast[i]->codec->bit_rate    = 2 * dv_audio_frequency[freq] * 16;
00231        c->ast[i]->start_time         = 0;
00232     }
00233     c->ach = i;
00234 
00235     return (c->sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */;
00236 }
00237 
00238 static int dv_extract_video_info(DVDemuxContext *c, uint8_t* frame)
00239 {
00240     const uint8_t* vsc_pack;
00241     AVCodecContext* avctx;
00242     int apt, is16_9;
00243     int size = 0;
00244 
00245     if (c->sys) {
00246         avctx = c->vst->codec;
00247 
00248         avpriv_set_pts_info(c->vst, 64, c->sys->time_base.num,
00249                         c->sys->time_base.den);
00250         avctx->time_base= c->sys->time_base;
00251         if (!avctx->width){
00252             avctx->width = c->sys->width;
00253             avctx->height = c->sys->height;
00254         }
00255         avctx->pix_fmt = c->sys->pix_fmt;
00256 
00257         /* finding out SAR is a little bit messy */
00258         vsc_pack = dv_extract_pack(frame, dv_video_control);
00259         apt      = frame[4] & 0x07;
00260         is16_9   = (vsc_pack && ((vsc_pack[2] & 0x07) == 0x02 ||
00261                                 (!apt && (vsc_pack[2] & 0x07) == 0x07)));
00262         c->vst->sample_aspect_ratio = c->sys->sar[is16_9];
00263         avctx->bit_rate = av_rescale_q(c->sys->frame_size, (AVRational){8,1},
00264                                        c->sys->time_base);
00265         size = c->sys->frame_size;
00266     }
00267     return size;
00268 }
00269 
00270 /*
00271  * The following 3 functions constitute our interface to the world
00272  */
00273 
00274 DVDemuxContext* avpriv_dv_init_demux(AVFormatContext *s)
00275 {
00276     DVDemuxContext *c;
00277 
00278     c = av_mallocz(sizeof(DVDemuxContext));
00279     if (!c)
00280         return NULL;
00281 
00282     c->vst = avformat_new_stream(s, NULL);
00283     if (!c->vst) {
00284         av_free(c);
00285         return NULL;
00286     }
00287 
00288     c->sys  = NULL;
00289     c->fctx = s;
00290     memset(c->ast, 0, sizeof(c->ast));
00291     c->ach    = 0;
00292     c->frames = 0;
00293     c->abytes = 0;
00294 
00295     c->vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00296     c->vst->codec->codec_id   = CODEC_ID_DVVIDEO;
00297     c->vst->codec->bit_rate   = 25000000;
00298     c->vst->start_time        = 0;
00299 
00300     return c;
00301 }
00302 
00303 int avpriv_dv_get_packet(DVDemuxContext *c, AVPacket *pkt)
00304 {
00305     int size = -1;
00306     int i;
00307 
00308     for (i = 0; i < c->ach; i++) {
00309        if (c->ast[i] && c->audio_pkt[i].size) {
00310            *pkt = c->audio_pkt[i];
00311            c->audio_pkt[i].size = 0;
00312            size = pkt->size;
00313            break;
00314        }
00315     }
00316 
00317     return size;
00318 }
00319 
00320 int avpriv_dv_produce_packet(DVDemuxContext *c, AVPacket *pkt,
00321                       uint8_t* buf, int buf_size)
00322 {
00323     int size, i;
00324     uint8_t *ppcm[4] = {0};
00325 
00326     if (buf_size < DV_PROFILE_BYTES ||
00327         !(c->sys = avpriv_dv_frame_profile(c->sys, buf, buf_size)) ||
00328         buf_size < c->sys->frame_size) {
00329           return -1;   /* Broken frame, or not enough data */
00330     }
00331 
00332     /* Queueing audio packet */
00333     /* FIXME: in case of no audio/bad audio we have to do something */
00334     size = dv_extract_audio_info(c, buf);
00335     for (i = 0; i < c->ach; i++) {
00336        c->audio_pkt[i].size = size;
00337        c->audio_pkt[i].pts  = c->abytes * 30000*8 / c->ast[i]->codec->bit_rate;
00338        ppcm[i] = c->audio_buf[i];
00339     }
00340     dv_extract_audio(buf, ppcm, c->sys);
00341 
00342     /* We work with 720p frames split in half, thus even frames have
00343      * channels 0,1 and odd 2,3. */
00344     if (c->sys->height == 720) {
00345         if (buf[1] & 0x0C) {
00346             c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
00347         } else {
00348             c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
00349             c->abytes += size;
00350         }
00351     } else {
00352         c->abytes += size;
00353     }
00354 
00355     /* Now it's time to return video packet */
00356     size = dv_extract_video_info(c, buf);
00357     av_init_packet(pkt);
00358     pkt->data         = buf;
00359     pkt->size         = size;
00360     pkt->flags       |= AV_PKT_FLAG_KEY;
00361     pkt->stream_index = c->vst->id;
00362     pkt->pts          = c->frames;
00363 
00364     c->frames++;
00365 
00366     return size;
00367 }
00368 
00369 static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c,
00370                               int64_t timestamp, int flags)
00371 {
00372     // FIXME: sys may be wrong if last dv_read_packet() failed (buffer is junk)
00373     const DVprofile* sys = avpriv_dv_codec_profile(c->vst->codec);
00374     int64_t offset;
00375     int64_t size = avio_size(s->pb) - s->data_offset;
00376     int64_t max_offset = ((size-1) / sys->frame_size) * sys->frame_size;
00377 
00378     offset = sys->frame_size * timestamp;
00379 
00380     if (size >= 0 && offset > max_offset) offset = max_offset;
00381     else if (offset < 0) offset = 0;
00382 
00383     return offset + s->data_offset;
00384 }
00385 
00386 void dv_offset_reset(DVDemuxContext *c, int64_t frame_offset)
00387 {
00388     c->frames= frame_offset;
00389     if (c->ach)
00390         c->abytes= av_rescale_q(c->frames, c->sys->time_base,
00391                                 (AVRational){8, c->ast[0]->codec->bit_rate});
00392     c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
00393     c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
00394 }
00395 
00396 /************************************************************
00397  * Implementation of the easiest DV storage of all -- raw DV.
00398  ************************************************************/
00399 
00400 typedef struct RawDVContext {
00401     DVDemuxContext* dv_demux;
00402     uint8_t         buf[DV_MAX_FRAME_SIZE];
00403 } RawDVContext;
00404 
00405 static int dv_read_header(AVFormatContext *s,
00406                           AVFormatParameters *ap)
00407 {
00408     unsigned state, marker_pos = 0;
00409     RawDVContext *c = s->priv_data;
00410 
00411     c->dv_demux = avpriv_dv_init_demux(s);
00412     if (!c->dv_demux)
00413         return -1;
00414 
00415     state = avio_rb32(s->pb);
00416     while ((state & 0xffffff7f) != 0x1f07003f) {
00417         if (s->pb->eof_reached) {
00418             av_log(s, AV_LOG_ERROR, "Cannot find DV header.\n");
00419             return -1;
00420         }
00421         if (state == 0x003f0700 || state == 0xff3f0700)
00422             marker_pos = avio_tell(s->pb);
00423         if (state == 0xff3f0701 && avio_tell(s->pb) - marker_pos == 80) {
00424             avio_seek(s->pb, -163, SEEK_CUR);
00425             state = avio_rb32(s->pb);
00426             break;
00427         }
00428         state = (state << 8) | avio_r8(s->pb);
00429     }
00430     AV_WB32(c->buf, state);
00431 
00432     if (avio_read(s->pb, c->buf + 4, DV_PROFILE_BYTES - 4) <= 0 ||
00433         avio_seek(s->pb, -DV_PROFILE_BYTES, SEEK_CUR) < 0)
00434         return AVERROR(EIO);
00435 
00436     c->dv_demux->sys = avpriv_dv_frame_profile(c->dv_demux->sys, c->buf, DV_PROFILE_BYTES);
00437     if (!c->dv_demux->sys) {
00438         av_log(s, AV_LOG_ERROR, "Can't determine profile of DV input stream.\n");
00439         return -1;
00440     }
00441 
00442     s->bit_rate = av_rescale_q(c->dv_demux->sys->frame_size, (AVRational){8,1},
00443                                c->dv_demux->sys->time_base);
00444 
00445     return 0;
00446 }
00447 
00448 
00449 static int dv_read_packet(AVFormatContext *s, AVPacket *pkt)
00450 {
00451     int size;
00452     RawDVContext *c = s->priv_data;
00453 
00454     size = avpriv_dv_get_packet(c->dv_demux, pkt);
00455 
00456     if (size < 0) {
00457         if (!c->dv_demux->sys)
00458             return AVERROR(EIO);
00459         size = c->dv_demux->sys->frame_size;
00460         if (avio_read(s->pb, c->buf, size) <= 0)
00461             return AVERROR(EIO);
00462 
00463         size = avpriv_dv_produce_packet(c->dv_demux, pkt, c->buf, size);
00464     }
00465 
00466     return size;
00467 }
00468 
00469 static int dv_read_seek(AVFormatContext *s, int stream_index,
00470                        int64_t timestamp, int flags)
00471 {
00472     RawDVContext *r   = s->priv_data;
00473     DVDemuxContext *c = r->dv_demux;
00474     int64_t offset    = dv_frame_offset(s, c, timestamp, flags);
00475 
00476     dv_offset_reset(c, offset / c->sys->frame_size);
00477 
00478     offset = avio_seek(s->pb, offset, SEEK_SET);
00479     return (offset < 0) ? offset : 0;
00480 }
00481 
00482 static int dv_read_close(AVFormatContext *s)
00483 {
00484     RawDVContext *c = s->priv_data;
00485     av_free(c->dv_demux);
00486     return 0;
00487 }
00488 
00489 static int dv_probe(AVProbeData *p)
00490 {
00491     unsigned state, marker_pos = 0;
00492     int i;
00493     int matches = 0;
00494     int secondary_matches = 0;
00495 
00496     if (p->buf_size < 5)
00497         return 0;
00498 
00499     state = AV_RB32(p->buf);
00500     for (i = 4; i < p->buf_size; i++) {
00501         if ((state & 0xffffff7f) == 0x1f07003f)
00502             matches++;
00503         // any section header, also with seq/chan num != 0,
00504         // should appear around every 12000 bytes, at least 10 per frame
00505         if ((state & 0xff07ff7f) == 0x1f07003f)
00506             secondary_matches++;
00507         if (state == 0x003f0700 || state == 0xff3f0700)
00508             marker_pos = i;
00509         if (state == 0xff3f0701 && i - marker_pos == 80)
00510             matches++;
00511         state = (state << 8) | p->buf[i];
00512     }
00513 
00514     if (matches && p->buf_size / matches < 1024*1024) {
00515         if (matches > 4 || (secondary_matches >= 10 && p->buf_size / secondary_matches < 24000))
00516             return AVPROBE_SCORE_MAX*3/4; // not max to avoid dv in mov to match
00517         return AVPROBE_SCORE_MAX/4;
00518     }
00519     return 0;
00520 }
00521 
00522 #if CONFIG_DV_DEMUXER
00523 AVInputFormat ff_dv_demuxer = {
00524     .name           = "dv",
00525     .long_name      = NULL_IF_CONFIG_SMALL("DV video format"),
00526     .priv_data_size = sizeof(RawDVContext),
00527     .read_probe     = dv_probe,
00528     .read_header    = dv_read_header,
00529     .read_packet    = dv_read_packet,
00530     .read_close     = dv_read_close,
00531     .read_seek      = dv_read_seek,
00532     .extensions = "dv,dif",
00533 };
00534 #endif
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