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/*
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 * General DV muxer/demuxer
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 * Copyright (c) 2003 Roman Shaposhnik
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 *
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 * Many thanks to Dan Dennedy <dan@dennedy.org> for providing wealth
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 * of DV technical info.
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 *
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 * Raw DV format
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 * Copyright (c) 2002 Fabrice Bellard.
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 *
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 * 50 Mbps (DVCPRO50) and 100 Mbps (DVCPRO HD) support
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 * Copyright (c) 2006 Daniel Maas <dmaas@maasdigital.com>
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 * Funded by BBC Research & Development
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#include <time.h>
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#include "avformat.h"
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#include "libavcodec/dvdata.h"
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#include "dv.h"
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struct DVDemuxContext {
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    const DVprofile*  sys;    /* Current DV profile. E.g.: 525/60, 625/50 */
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    AVFormatContext* fctx;
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    AVStream*        vst;
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    AVStream*        ast[4];
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    AVPacket         audio_pkt[4];
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    uint8_t          audio_buf[4][8192];
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    int              ach;
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    int              frames;
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    uint64_t         abytes;
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};
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static inline uint16_t dv_audio_12to16(uint16_t sample)
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{
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    uint16_t shift, result;
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    sample = (sample < 0x800) ? sample : sample | 0xf000;
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    shift = (sample & 0xf00) >> 8;
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    if (shift < 0x2 || shift > 0xd) {
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        result = sample;
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    } else if (shift < 0x8) {
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        shift--;
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        result = (sample - (256 * shift)) << shift;
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    } else {
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        shift = 0xe - shift;
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        result = ((sample + ((256 * shift) + 1)) << shift) - 1;
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    }
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    return result;
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}
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/*
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 * This is the dumbest implementation of all -- it simply looks at
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 * a fixed offset and if pack isn't there -- fails. We might want
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 * to have a fallback mechanism for complete search of missing packs.
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 */
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static const uint8_t* dv_extract_pack(uint8_t* frame, enum dv_pack_type t)
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{
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    int offs;
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    switch (t) {
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    case dv_audio_source:
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          offs = (80*6 + 80*16*3 + 3);
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          break;
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    case dv_audio_control:
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          offs = (80*6 + 80*16*4 + 3);
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          break;
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    case dv_video_control:
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          offs = (80*5 + 48 + 5);
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          break;
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    default:
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          return NULL;
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    }
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    return frame[offs] == t ? &frame[offs] : NULL;
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}
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/*
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 * There's a couple of assumptions being made here:
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 * 1. By default we silence erroneous (0x8000/16bit 0x800/12bit) audio samples.
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 *    We can pass them upwards when ffmpeg will be ready to deal with them.
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 * 2. We don't do software emphasis.
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 * 3. Audio is always returned as 16bit linear samples: 12bit nonlinear samples
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 *    are converted into 16bit linear ones.
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 */
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static int dv_extract_audio(uint8_t* frame, uint8_t* ppcm[4],
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                            const DVprofile *sys)
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{
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    int size, chan, i, j, d, of, smpls, freq, quant, half_ch;
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    uint16_t lc, rc;
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    const uint8_t* as_pack;
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    uint8_t *pcm, ipcm;
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    as_pack = dv_extract_pack(frame, dv_audio_source);
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    if (!as_pack)    /* No audio ? */
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        return 0;
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    smpls = as_pack[1] & 0x3f; /* samples in this frame - min. samples */
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    freq = (as_pack[4] >> 3) & 0x07; /* 0 - 48KHz, 1 - 44,1kHz, 2 - 32 kHz */
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    quant = as_pack[4] & 0x07; /* 0 - 16bit linear, 1 - 12bit nonlinear */
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    if (quant > 1)
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        return -1; /* Unsupported quantization */
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    size = (sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */
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    half_ch = sys->difseg_size/2;
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    /* We work with 720p frames split in half, thus even frames have channels 0,1 and odd 2,3 */
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    ipcm = (sys->height == 720 && ((frame[1]>>2)&0x3) == 0)?2:0;
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    pcm = ppcm[ipcm++];
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    /* for each DIF channel */
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    for (chan = 0; chan < sys->n_difchan; chan++) {
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        /* for each DIF segment */
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        for (i = 0; i < sys->difseg_size; i++) {
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            frame += 6 * 80; /* skip DIF segment header */
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            if (quant == 1 && i == half_ch) {
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                /* next stereo channel (12bit mode only) */
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                pcm = ppcm[ipcm++];
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                if (!pcm)
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                    break;
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            }
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            /* for each AV sequence */
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            for (j = 0; j < 9; j++) {
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                for (d = 8; d < 80; d += 2) {
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                    if (quant == 0) {  /* 16bit quantization */
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                        of = sys->audio_shuffle[i][j] + (d - 8)/2 * sys->audio_stride;
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                        if (of*2 >= size)
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                            continue;
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                        pcm[of*2] = frame[d+1]; // FIXME: may be we have to admit
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                        pcm[of*2+1] = frame[d]; //        that DV is a big endian PCM
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                        if (pcm[of*2+1] == 0x80 && pcm[of*2] == 0x00)
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                            pcm[of*2+1] = 0;
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                    } else {           /* 12bit quantization */
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                        lc = ((uint16_t)frame[d] << 4) |
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                             ((uint16_t)frame[d+2] >> 4);
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                        rc = ((uint16_t)frame[d+1] << 4) |
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                             ((uint16_t)frame[d+2] & 0x0f);
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                        lc = (lc == 0x800 ? 0 : dv_audio_12to16(lc));
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                        rc = (rc == 0x800 ? 0 : dv_audio_12to16(rc));
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                        of = sys->audio_shuffle[i%half_ch][j] + (d - 8)/3 * sys->audio_stride;
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                        if (of*2 >= size)
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                            continue;
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                        pcm[of*2] = lc & 0xff; // FIXME: may be we have to admit
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                        pcm[of*2+1] = lc >> 8; //        that DV is a big endian PCM
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                        of = sys->audio_shuffle[i%half_ch+half_ch][j] +
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                            (d - 8)/3 * sys->audio_stride;
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                        pcm[of*2] = rc & 0xff; // FIXME: may be we have to admit
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                        pcm[of*2+1] = rc >> 8; //        that DV is a big endian PCM
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                        ++d;
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                    }
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                }
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                frame += 16 * 80; /* 15 Video DIFs + 1 Audio DIF */
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            }
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        }
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        /* next stereo channel (50Mbps and 100Mbps only) */
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        pcm = ppcm[ipcm++];
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        if (!pcm)
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            break;
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    }
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    return size;
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}
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static int dv_extract_audio_info(DVDemuxContext* c, uint8_t* frame)
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{
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    const uint8_t* as_pack;
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    int freq, stype, smpls, quant, i, ach;
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    as_pack = dv_extract_pack(frame, dv_audio_source);
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    if (!as_pack || !c->sys) {    /* No audio ? */
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        c->ach = 0;
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        return 0;
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    }
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    smpls = as_pack[1] & 0x3f; /* samples in this frame - min. samples */
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    freq = (as_pack[4] >> 3) & 0x07; /* 0 - 48KHz, 1 - 44,1kHz, 2 - 32 kHz */
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    stype = (as_pack[3] & 0x1f); /* 0 - 2CH, 2 - 4CH, 3 - 8CH */
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    quant = as_pack[4] & 0x07; /* 0 - 16bit linear, 1 - 12bit nonlinear */
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    /* note: ach counts PAIRS of channels (i.e. stereo channels) */
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    if (stype == 3) {
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        ach = 4;
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    } else
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    ach = (stype == 2 || (quant && (freq == 2))) ? 2 : 1;
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    /* Dynamic handling of the audio streams in DV */
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    for (i=0; i<ach; i++) {
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       if (!c->ast[i]) {
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           c->ast[i] = av_new_stream(c->fctx, 0);
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           if (!c->ast[i])
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               break;
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           av_set_pts_info(c->ast[i], 64, 1, 30000);
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           c->ast[i]->codec->codec_type = CODEC_TYPE_AUDIO;
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           c->ast[i]->codec->codec_id = CODEC_ID_PCM_S16LE;
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           av_init_packet(&c->audio_pkt[i]);
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           c->audio_pkt[i].size     = 0;
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           c->audio_pkt[i].data     = c->audio_buf[i];
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           c->audio_pkt[i].stream_index = c->ast[i]->index;
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           c->audio_pkt[i].flags |= PKT_FLAG_KEY;
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       }
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       c->ast[i]->codec->sample_rate = dv_audio_frequency[freq];
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       c->ast[i]->codec->channels = 2;
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       c->ast[i]->codec->bit_rate = 2 * dv_audio_frequency[freq] * 16;
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       c->ast[i]->start_time = 0;
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    }
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    c->ach = i;
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    return (c->sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */;
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}
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static int dv_extract_video_info(DVDemuxContext *c, uint8_t* frame)
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{
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    const uint8_t* vsc_pack;
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    AVCodecContext* avctx;
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    int apt, is16_9;
240
    int size = 0;
241

    
242
    if (c->sys) {
243
        avctx = c->vst->codec;
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245
        av_set_pts_info(c->vst, 64, c->sys->frame_rate_base, c->sys->frame_rate);
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        avctx->time_base= (AVRational){c->sys->frame_rate_base, c->sys->frame_rate};
247
        if(!avctx->width){
248
            avctx->width = c->sys->width;
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            avctx->height = c->sys->height;
250
        }
251
        avctx->pix_fmt = c->sys->pix_fmt;
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253
        /* finding out SAR is a little bit messy */
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        vsc_pack = dv_extract_pack(frame, dv_video_control);
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        apt = frame[4] & 0x07;
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        is16_9 = (vsc_pack && ((vsc_pack[2] & 0x07) == 0x02 ||
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                               (!apt && (vsc_pack[2] & 0x07) == 0x07)));
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        c->vst->sample_aspect_ratio = c->sys->sar[is16_9];
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        avctx->bit_rate = av_rescale(c->sys->frame_size * 8,
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                                     c->sys->frame_rate,
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                                     c->sys->frame_rate_base);
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        size = c->sys->frame_size;
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    }
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    return size;
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}
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/*
268
 * The following 3 functions constitute our interface to the world
269
 */
270

    
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DVDemuxContext* dv_init_demux(AVFormatContext *s)
272
{
273
    DVDemuxContext *c;
274

    
275
    c = av_mallocz(sizeof(DVDemuxContext));
276
    if (!c)
277
        return NULL;
278

    
279
    c->vst = av_new_stream(s, 0);
280
    if (!c->vst) {
281
        av_free(c);
282
        return NULL;
283
    }
284

    
285
    c->sys = NULL;
286
    c->fctx = s;
287
    memset(c->ast, 0, sizeof(c->ast));
288
    c->ach = 0;
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    c->frames = 0;
290
    c->abytes = 0;
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292
    c->vst->codec->codec_type = CODEC_TYPE_VIDEO;
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    c->vst->codec->codec_id = CODEC_ID_DVVIDEO;
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    c->vst->codec->bit_rate = 25000000;
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    c->vst->start_time = 0;
296

    
297
    return c;
298
}
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300
int dv_get_packet(DVDemuxContext *c, AVPacket *pkt)
301
{
302
    int size = -1;
303
    int i;
304

    
305
    for (i=0; i<c->ach; i++) {
306
       if (c->ast[i] && c->audio_pkt[i].size) {
307
           *pkt = c->audio_pkt[i];
308
           c->audio_pkt[i].size = 0;
309
           size = pkt->size;
310
           break;
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       }
312
    }
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314
    return size;
315
}
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int dv_produce_packet(DVDemuxContext *c, AVPacket *pkt,
318
                      uint8_t* buf, int buf_size)
319
{
320
    int size, i;
321
    uint8_t *ppcm[4] = {0};
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323
    if (buf_size < DV_PROFILE_BYTES ||
324
        !(c->sys = dv_frame_profile(buf)) ||
325
        buf_size < c->sys->frame_size) {
326
          return -1;   /* Broken frame, or not enough data */
327
    }
328

    
329
    /* Queueing audio packet */
330
    /* FIXME: in case of no audio/bad audio we have to do something */
331
    size = dv_extract_audio_info(c, buf);
332
    for (i=0; i<c->ach; i++) {
333
       c->audio_pkt[i].size = size;
334
       c->audio_pkt[i].pts  = c->abytes * 30000*8 / c->ast[i]->codec->bit_rate;
335
       ppcm[i] = c->audio_buf[i];
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    }
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    dv_extract_audio(buf, ppcm, c->sys);
338
    c->abytes += size;
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340
    /* We work with 720p frames split in half, thus even frames have channels 0,1 and odd 2,3 */
341
    if (c->sys->height == 720) {
342
        if (((buf[1]>>2)&0x3))
343
            c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
344
        else
345
            c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
346
    }
347

    
348
    /* Now it's time to return video packet */
349
    size = dv_extract_video_info(c, buf);
350
    av_init_packet(pkt);
351
    pkt->data     = buf;
352
    pkt->size     = size;
353
    pkt->flags   |= PKT_FLAG_KEY;
354
    pkt->stream_index = c->vst->id;
355
    pkt->pts      = c->frames;
356

    
357
    c->frames++;
358

    
359
    return size;
360
}
361

    
362
static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c,
363
                              int64_t timestamp, int flags)
364
{
365
    // FIXME: sys may be wrong if last dv_read_packet() failed (buffer is junk)
366
    const DVprofile* sys = dv_codec_profile(c->vst->codec);
367
    int64_t offset;
368
    int64_t size = url_fsize(s->pb);
369
    int64_t max_offset = ((size-1) / sys->frame_size) * sys->frame_size;
370

    
371
    offset = sys->frame_size * timestamp;
372

    
373
    if (offset > max_offset) offset = max_offset;
374
    else if (offset < 0) offset = 0;
375

    
376
    return offset;
377
}
378

    
379
void dv_offset_reset(DVDemuxContext *c, int64_t frame_offset)
380
{
381
    c->frames= frame_offset;
382
    if (c->ach)
383
        c->abytes= av_rescale(c->frames,
384
                          c->ast[0]->codec->bit_rate * (int64_t)c->sys->frame_rate_base,
385
                          8*c->sys->frame_rate);
386
    c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
387
    c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
388
}
389

    
390
/************************************************************
391
 * Implementation of the easiest DV storage of all -- raw DV.
392
 ************************************************************/
393

    
394
typedef struct RawDVContext {
395
    DVDemuxContext* dv_demux;
396
    uint8_t         buf[DV_MAX_FRAME_SIZE];
397
} RawDVContext;
398

    
399
static int dv_read_header(AVFormatContext *s,
400
                          AVFormatParameters *ap)
401
{
402
    RawDVContext *c = s->priv_data;
403

    
404
    c->dv_demux = dv_init_demux(s);
405
    if (!c->dv_demux)
406
        return -1;
407

    
408
    if (get_buffer(s->pb, c->buf, DV_PROFILE_BYTES) <= 0 ||
409
        url_fseek(s->pb, -DV_PROFILE_BYTES, SEEK_CUR) < 0)
410
        return AVERROR(EIO);
411

    
412
    c->dv_demux->sys = dv_frame_profile(c->buf);
413
    if (!c->dv_demux->sys) {
414
        av_log(s, AV_LOG_ERROR, "Can't determine profile of DV input stream.\n");
415
        return -1;
416
    }
417

    
418
    s->bit_rate = av_rescale(c->dv_demux->sys->frame_size * 8,
419
                             c->dv_demux->sys->frame_rate,
420
                             c->dv_demux->sys->frame_rate_base);
421

    
422
    return 0;
423
}
424

    
425

    
426
static int dv_read_packet(AVFormatContext *s, AVPacket *pkt)
427
{
428
    int size;
429
    RawDVContext *c = s->priv_data;
430

    
431
    size = dv_get_packet(c->dv_demux, pkt);
432

    
433
    if (size < 0) {
434
        size = c->dv_demux->sys->frame_size;
435
        if (get_buffer(s->pb, c->buf, size) <= 0)
436
            return AVERROR(EIO);
437

    
438
        size = dv_produce_packet(c->dv_demux, pkt, c->buf, size);
439
    }
440

    
441
    return size;
442
}
443

    
444
static int dv_read_seek(AVFormatContext *s, int stream_index,
445
                       int64_t timestamp, int flags)
446
{
447
    RawDVContext *r = s->priv_data;
448
    DVDemuxContext *c = r->dv_demux;
449
    int64_t offset= dv_frame_offset(s, c, timestamp, flags);
450

    
451
    dv_offset_reset(c, offset / c->sys->frame_size);
452

    
453
    offset = url_fseek(s->pb, offset, SEEK_SET);
454
    return (offset < 0)?offset:0;
455
}
456

    
457
static int dv_read_close(AVFormatContext *s)
458
{
459
    RawDVContext *c = s->priv_data;
460
    av_free(c->dv_demux);
461
    return 0;
462
}
463

    
464
#ifdef CONFIG_DV_DEMUXER
465
AVInputFormat dv_demuxer = {
466
    "dv",
467
    NULL_IF_CONFIG_SMALL("DV video format"),
468
    sizeof(RawDVContext),
469
    NULL,
470
    dv_read_header,
471
    dv_read_packet,
472
    dv_read_close,
473
    dv_read_seek,
474
    .extensions = "dv,dif",
475
};
476
#endif