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1
/*
2
 * 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 "libavutil/intreadwrite.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)
50
{
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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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56
    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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    }
65

    
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    return result;
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}
68

    
69
/*
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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)
75
{
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    int offs;
77

    
78
    switch (t) {
79
    case dv_audio_source:
80
        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;
85
    case dv_video_control:
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        offs = (80*5 + 48 + 5);
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        break;
88
    default:
89
        return NULL;
90
    }
91

    
92
    return frame[offs] == t ? &frame[offs] : NULL;
93
}
94

    
95
/*
96
 * 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.
98
 *    We can pass them upwards when ffmpeg will be ready to deal with them.
99
 * 2. We don't do software emphasis.
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 * 3. Audio is always returned as 16bit linear samples: 12bit nonlinear samples
101
 *    are converted into 16bit linear ones.
102
 */
103
static int dv_extract_audio(uint8_t* frame, uint8_t* ppcm[4],
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                            const DVprofile *sys)
105
{
106
    int size, chan, i, j, d, of, smpls, freq, quant, half_ch;
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    uint16_t lc, rc;
108
    const uint8_t* as_pack;
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    uint8_t *pcm, ipcm;
110

    
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    as_pack = dv_extract_pack(frame, dv_audio_source);
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    if (!as_pack)    /* No audio ? */
113
        return 0;
114

    
115
    smpls =  as_pack[1] & 0x3f;       /* samples in this frame - min. samples */
116
    freq  = (as_pack[4] >> 3) & 0x07; /* 0 - 48kHz, 1 - 44,1kHz, 2 - 32kHz */
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    quant =  as_pack[4] & 0x07;       /* 0 - 16bit linear, 1 - 12bit nonlinear */
118

    
119
    if (quant > 1)
120
        return -1; /* unsupported quantization */
121

    
122
    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
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     * channels 0,1 and odd 2,3. */
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    ipcm = (sys->height == 720 && !(frame[1] & 0x0C)) ? 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 */
135
            if (quant == 1 && i == half_ch) {
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                /* next stereo channel (12bit mode only) */
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                pcm = ppcm[ipcm++];
138
                if (!pcm)
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                    break;
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            }
141

    
142
            /* for each AV sequence */
143
            for (j = 0; j < 9; j++) {
144
                for (d = 8; d < 80; d += 2) {
145
                    if (quant == 0) {  /* 16bit quantization */
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                        of = sys->audio_shuffle[i][j] + (d - 8) / 2 * sys->audio_stride;
147
                        if (of*2 >= size)
148
                            continue;
149

    
150
                        pcm[of*2]   = frame[d+1]; // FIXME: maybe we have to admit
151
                        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;
154
                    } else {           /* 12bit quantization */
155
                        lc = ((uint16_t)frame[d]   << 4) |
156
                             ((uint16_t)frame[d+2] >> 4);
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                        rc = ((uint16_t)frame[d+1] << 4) |
158
                             ((uint16_t)frame[d+2] & 0x0f);
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                        lc = (lc == 0x800 ? 0 : dv_audio_12to16(lc));
160
                        rc = (rc == 0x800 ? 0 : dv_audio_12to16(rc));
161

    
162
                        of = sys->audio_shuffle[i%half_ch][j] + (d - 8) / 3 * sys->audio_stride;
163
                        if (of*2 >= size)
164
                            continue;
165

    
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                        pcm[of*2]   = lc & 0xff; // FIXME: maybe 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: maybe we have to admit
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                        pcm[of*2+1] = rc >> 8;   //        that DV is a big-endian PCM
172
                        ++d;
173
                    }
174
                }
175

    
176
                frame += 16 * 80; /* 15 Video DIFs + 1 Audio DIF */
177
            }
178
        }
179

    
180
        /* next stereo channel (50Mbps and 100Mbps only) */
181
        pcm = ppcm[ipcm++];
182
        if (!pcm)
183
            break;
184
    }
185

    
186
    return size;
187
}
188

    
189
static int dv_extract_audio_info(DVDemuxContext* c, uint8_t* frame)
190
{
191
    const uint8_t* as_pack;
192
    int freq, stype, smpls, quant, i, ach;
193

    
194
    as_pack = dv_extract_pack(frame, dv_audio_source);
195
    if (!as_pack || !c->sys) {    /* No audio ? */
196
        c->ach = 0;
197
        return 0;
198
    }
199

    
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    smpls =  as_pack[1] & 0x3f;       /* samples in this frame - min. samples */
201
    freq  = (as_pack[4] >> 3) & 0x07; /* 0 - 48kHz, 1 - 44,1kHz, 2 - 32kHz */
202
    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 */
204

    
205
    /* note: ach counts PAIRS of channels (i.e. stereo channels) */
206
    ach = ((int[4]){  1,  0,  2,  4})[stype];
207
    if (ach == 1 && quant && freq == 2)
208
        ach = 2;
209

    
210
    /* Dynamic handling of the audio streams in DV */
211
    for (i = 0; i < ach; i++) {
212
       if (!c->ast[i]) {
213
           c->ast[i] = av_new_stream(c->fctx, 0);
214
           if (!c->ast[i])
215
               break;
216
           av_set_pts_info(c->ast[i], 64, 1, 30000);
217
           c->ast[i]->codec->codec_type = AVMEDIA_TYPE_AUDIO;
218
           c->ast[i]->codec->codec_id   = CODEC_ID_PCM_S16LE;
219

    
220
           av_init_packet(&c->audio_pkt[i]);
221
           c->audio_pkt[i].size         = 0;
222
           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       |= AV_PKT_FLAG_KEY;
225
       }
226
       c->ast[i]->codec->sample_rate = dv_audio_frequency[freq];
227
       c->ast[i]->codec->channels    = 2;
228
       c->ast[i]->codec->bit_rate    = 2 * dv_audio_frequency[freq] * 16;
229
       c->ast[i]->start_time         = 0;
230
    }
231
    c->ach = i;
232

    
233
    return (c->sys->audio_min_samples[freq] + smpls) * 4; /* 2ch, 2bytes */;
234
}
235

    
236
static int dv_extract_video_info(DVDemuxContext *c, uint8_t* frame)
237
{
238
    const uint8_t* vsc_pack;
239
    AVCodecContext* avctx;
240
    int apt, is16_9;
241
    int size = 0;
242

    
243
    if (c->sys) {
244
        avctx = c->vst->codec;
245

    
246
        av_set_pts_info(c->vst, 64, c->sys->time_base.num,
247
                        c->sys->time_base.den);
248
        avctx->time_base= c->sys->time_base;
249
        if (!avctx->width){
250
            avctx->width = c->sys->width;
251
            avctx->height = c->sys->height;
252
        }
253
        avctx->pix_fmt = c->sys->pix_fmt;
254

    
255
        /* finding out SAR is a little bit messy */
256
        vsc_pack = dv_extract_pack(frame, dv_video_control);
257
        apt      = frame[4] & 0x07;
258
        is16_9   = (vsc_pack && ((vsc_pack[2] & 0x07) == 0x02 ||
259
                                (!apt && (vsc_pack[2] & 0x07) == 0x07)));
260
        c->vst->sample_aspect_ratio = c->sys->sar[is16_9];
261
        avctx->bit_rate = av_rescale_q(c->sys->frame_size, (AVRational){8,1},
262
                                       c->sys->time_base);
263
        size = c->sys->frame_size;
264
    }
265
    return size;
266
}
267

    
268
/*
269
 * The following 3 functions constitute our interface to the world
270
 */
271

    
272
DVDemuxContext* dv_init_demux(AVFormatContext *s)
273
{
274
    DVDemuxContext *c;
275

    
276
    c = av_mallocz(sizeof(DVDemuxContext));
277
    if (!c)
278
        return NULL;
279

    
280
    c->vst = av_new_stream(s, 0);
281
    if (!c->vst) {
282
        av_free(c);
283
        return NULL;
284
    }
285

    
286
    c->sys  = NULL;
287
    c->fctx = s;
288
    memset(c->ast, 0, sizeof(c->ast));
289
    c->ach    = 0;
290
    c->frames = 0;
291
    c->abytes = 0;
292

    
293
    c->vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;
294
    c->vst->codec->codec_id   = CODEC_ID_DVVIDEO;
295
    c->vst->codec->bit_rate   = 25000000;
296
    c->vst->start_time        = 0;
297

    
298
    return c;
299
}
300

    
301
int dv_get_packet(DVDemuxContext *c, AVPacket *pkt)
302
{
303
    int size = -1;
304
    int i;
305

    
306
    for (i = 0; i < c->ach; i++) {
307
       if (c->ast[i] && c->audio_pkt[i].size) {
308
           *pkt = c->audio_pkt[i];
309
           c->audio_pkt[i].size = 0;
310
           size = pkt->size;
311
           break;
312
       }
313
    }
314

    
315
    return size;
316
}
317

    
318
int dv_produce_packet(DVDemuxContext *c, AVPacket *pkt,
319
                      uint8_t* buf, int buf_size)
320
{
321
    int size, i;
322
    uint8_t *ppcm[4] = {0};
323

    
324
    if (buf_size < DV_PROFILE_BYTES ||
325
        !(c->sys = ff_dv_frame_profile(c->sys, buf, buf_size)) ||
326
        buf_size < c->sys->frame_size) {
327
          return -1;   /* Broken frame, or not enough data */
328
    }
329

    
330
    /* Queueing audio packet */
331
    /* FIXME: in case of no audio/bad audio we have to do something */
332
    size = dv_extract_audio_info(c, buf);
333
    for (i = 0; i < c->ach; i++) {
334
       c->audio_pkt[i].size = size;
335
       c->audio_pkt[i].pts  = c->abytes * 30000*8 / c->ast[i]->codec->bit_rate;
336
       ppcm[i] = c->audio_buf[i];
337
    }
338
    dv_extract_audio(buf, ppcm, c->sys);
339

    
340
    /* We work with 720p frames split in half, thus even frames have
341
     * channels 0,1 and odd 2,3. */
342
    if (c->sys->height == 720) {
343
        if (buf[1] & 0x0C) {
344
            c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
345
        } else {
346
            c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
347
            c->abytes += size;
348
        }
349
    } else {
350
        c->abytes += size;
351
    }
352

    
353
    /* Now it's time to return video packet */
354
    size = dv_extract_video_info(c, buf);
355
    av_init_packet(pkt);
356
    pkt->data         = buf;
357
    pkt->size         = size;
358
    pkt->flags       |= AV_PKT_FLAG_KEY;
359
    pkt->stream_index = c->vst->id;
360
    pkt->pts          = c->frames;
361

    
362
    c->frames++;
363

    
364
    return size;
365
}
366

    
367
static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c,
368
                              int64_t timestamp, int flags)
369
{
370
    // FIXME: sys may be wrong if last dv_read_packet() failed (buffer is junk)
371
    const DVprofile* sys = ff_dv_codec_profile(c->vst->codec);
372
    int64_t offset;
373
    int64_t size = url_fsize(s->pb) - s->data_offset;
374
    int64_t max_offset = ((size-1) / sys->frame_size) * sys->frame_size;
375

    
376
    offset = sys->frame_size * timestamp;
377

    
378
    if (size >= 0 && offset > max_offset) offset = max_offset;
379
    else if (offset < 0) offset = 0;
380

    
381
    return offset + s->data_offset;
382
}
383

    
384
void dv_offset_reset(DVDemuxContext *c, int64_t frame_offset)
385
{
386
    c->frames= frame_offset;
387
    if (c->ach)
388
        c->abytes= av_rescale_q(c->frames, c->sys->time_base,
389
                                (AVRational){8, c->ast[0]->codec->bit_rate});
390
    c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
391
    c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
392
}
393

    
394
/************************************************************
395
 * Implementation of the easiest DV storage of all -- raw DV.
396
 ************************************************************/
397

    
398
typedef struct RawDVContext {
399
    DVDemuxContext* dv_demux;
400
    uint8_t         buf[DV_MAX_FRAME_SIZE];
401
} RawDVContext;
402

    
403
static int dv_read_header(AVFormatContext *s,
404
                          AVFormatParameters *ap)
405
{
406
    unsigned state, marker_pos = 0;
407
    RawDVContext *c = s->priv_data;
408

    
409
    c->dv_demux = dv_init_demux(s);
410
    if (!c->dv_demux)
411
        return -1;
412

    
413
    state = avio_rb32(s->pb);
414
    while ((state & 0xffffff7f) != 0x1f07003f) {
415
        if (url_feof(s->pb)) {
416
            av_log(s, AV_LOG_ERROR, "Cannot find DV header.\n");
417
            return -1;
418
        }
419
        if (state == 0x003f0700 || state == 0xff3f0700)
420
            marker_pos = url_ftell(s->pb);
421
        if (state == 0xff3f0701 && url_ftell(s->pb) - marker_pos == 80) {
422
            url_fseek(s->pb, -163, SEEK_CUR);
423
            state = avio_rb32(s->pb);
424
            break;
425
        }
426
        state = (state << 8) | avio_r8(s->pb);
427
    }
428
    AV_WB32(c->buf, state);
429

    
430
    if (avio_read(s->pb, c->buf + 4, DV_PROFILE_BYTES - 4) <= 0 ||
431
        url_fseek(s->pb, -DV_PROFILE_BYTES, SEEK_CUR) < 0)
432
        return AVERROR(EIO);
433

    
434
    c->dv_demux->sys = ff_dv_frame_profile(c->dv_demux->sys, c->buf, DV_PROFILE_BYTES);
435
    if (!c->dv_demux->sys) {
436
        av_log(s, AV_LOG_ERROR, "Can't determine profile of DV input stream.\n");
437
        return -1;
438
    }
439

    
440
    s->bit_rate = av_rescale_q(c->dv_demux->sys->frame_size, (AVRational){8,1},
441
                               c->dv_demux->sys->time_base);
442

    
443
    return 0;
444
}
445

    
446

    
447
static int dv_read_packet(AVFormatContext *s, AVPacket *pkt)
448
{
449
    int size;
450
    RawDVContext *c = s->priv_data;
451

    
452
    size = dv_get_packet(c->dv_demux, pkt);
453

    
454
    if (size < 0) {
455
        if (!c->dv_demux->sys)
456
            return AVERROR(EIO);
457
        size = c->dv_demux->sys->frame_size;
458
        if (avio_read(s->pb, c->buf, size) <= 0)
459
            return AVERROR(EIO);
460

    
461
        size = dv_produce_packet(c->dv_demux, pkt, c->buf, size);
462
    }
463

    
464
    return size;
465
}
466

    
467
static int dv_read_seek(AVFormatContext *s, int stream_index,
468
                       int64_t timestamp, int flags)
469
{
470
    RawDVContext *r   = s->priv_data;
471
    DVDemuxContext *c = r->dv_demux;
472
    int64_t offset    = dv_frame_offset(s, c, timestamp, flags);
473

    
474
    dv_offset_reset(c, offset / c->sys->frame_size);
475

    
476
    offset = url_fseek(s->pb, offset, SEEK_SET);
477
    return (offset < 0) ? offset : 0;
478
}
479

    
480
static int dv_read_close(AVFormatContext *s)
481
{
482
    RawDVContext *c = s->priv_data;
483
    av_free(c->dv_demux);
484
    return 0;
485
}
486

    
487
static int dv_probe(AVProbeData *p)
488
{
489
    unsigned state, marker_pos = 0;
490
    int i;
491
    int matches = 0;
492
    int secondary_matches = 0;
493

    
494
    if (p->buf_size < 5)
495
        return 0;
496

    
497
    state = AV_RB32(p->buf);
498
    for (i = 4; i < p->buf_size; i++) {
499
        if ((state & 0xffffff7f) == 0x1f07003f)
500
            matches++;
501
        // any section header, also with seq/chan num != 0,
502
        // should appear around every 12000 bytes, at least 10 per frame
503
        if ((state & 0xff07ff7f) == 0x1f07003f)
504
            secondary_matches++;
505
        if (state == 0x003f0700 || state == 0xff3f0700)
506
            marker_pos = i;
507
        if (state == 0xff3f0701 && i - marker_pos == 80)
508
            matches++;
509
        state = (state << 8) | p->buf[i];
510
    }
511

    
512
    if (matches && p->buf_size / matches < 1024*1024) {
513
        if (matches > 4 || (secondary_matches >= 10 && p->buf_size / secondary_matches < 24000))
514
            return AVPROBE_SCORE_MAX*3/4; // not max to avoid dv in mov to match
515
        return AVPROBE_SCORE_MAX/4;
516
    }
517
    return 0;
518
}
519

    
520
#if CONFIG_DV_DEMUXER
521
AVInputFormat ff_dv_demuxer = {
522
    "dv",
523
    NULL_IF_CONFIG_SMALL("DV video format"),
524
    sizeof(RawDVContext),
525
    dv_probe,
526
    dv_read_header,
527
    dv_read_packet,
528
    dv_read_close,
529
    dv_read_seek,
530
    .extensions = "dv,dif",
531
};
532
#endif