summaryrefslogtreecommitdiff
path: root/libavcodec/dvdec.c
blob: bc1bb55eb9ee07e171cafe84c5f3bdfaadb1fe2a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
/*
 * DV decoder
 * Copyright (c) 2002 Fabrice Bellard
 * Copyright (c) 2004 Roman Shaposhnik
 *
 * 50 Mbps (DVCPRO50) support
 * Copyright (c) 2006 Daniel Maas <dmaas@maasdigital.com>
 *
 * 100 Mbps (DVCPRO HD) support
 * Initial code by Daniel Maas <dmaas@maasdigital.com> (funded by BBC R&D)
 * Final code by Roman Shaposhnik
 *
 * Many thanks to Dan Dennedy <dan@dennedy.org> for providing wealth
 * of DV technical info.
 *
 * This file is part of Libav.
 *
 * Libav is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * Libav is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * DV decoder
 */

#include "libavutil/pixdesc.h"
#include "avcodec.h"
#include "dsputil.h"
#include "internal.h"
#include "get_bits.h"
#include "put_bits.h"
#include "simple_idct.h"
#include "dvdata.h"

typedef struct BlockInfo {
    const uint32_t *factor_table;
    const uint8_t *scan_table;
    uint8_t pos; /* position in block */
    void (*idct_put)(uint8_t *dest, int line_size, DCTELEM *block);
    uint8_t partial_bit_count;
    uint32_t partial_bit_buffer;
    int shift_offset;
} BlockInfo;

static const int dv_iweight_bits = 14;

/* decode AC coefficients */
static void dv_decode_ac(GetBitContext *gb, BlockInfo *mb, DCTELEM *block)
{
    int last_index = gb->size_in_bits;
    const uint8_t  *scan_table   = mb->scan_table;
    const uint32_t *factor_table = mb->factor_table;
    int pos               = mb->pos;
    int partial_bit_count = mb->partial_bit_count;
    int level, run, vlc_len, index;

    OPEN_READER(re, gb);
    UPDATE_CACHE(re, gb);

    /* if we must parse a partial VLC, we do it here */
    if (partial_bit_count > 0) {
        re_cache = re_cache >> partial_bit_count | mb->partial_bit_buffer;
        re_index -= partial_bit_count;
        mb->partial_bit_count = 0;
    }

    /* get the AC coefficients until last_index is reached */
    for (;;) {
        av_dlog(NULL, "%2d: bits=%04x index=%d\n", pos, SHOW_UBITS(re, gb, 16),
                re_index);
        /* our own optimized GET_RL_VLC */
        index   = NEG_USR32(re_cache, TEX_VLC_BITS);
        vlc_len = ff_dv_rl_vlc[index].len;
        if (vlc_len < 0) {
            index = NEG_USR32((unsigned)re_cache << TEX_VLC_BITS, -vlc_len) +
                    ff_dv_rl_vlc[index].level;
            vlc_len = TEX_VLC_BITS - vlc_len;
        }
        level = ff_dv_rl_vlc[index].level;
        run   = ff_dv_rl_vlc[index].run;

        /* gotta check if we're still within gb boundaries */
        if (re_index + vlc_len > last_index) {
            /* should be < 16 bits otherwise a codeword could have been parsed */
            mb->partial_bit_count = last_index - re_index;
            mb->partial_bit_buffer = re_cache & ~(-1u >> mb->partial_bit_count);
            re_index = last_index;
            break;
        }
        re_index += vlc_len;

        av_dlog(NULL, "run=%d level=%d\n", run, level);
        pos += run;
        if (pos >= 64)
            break;

        level = (level * factor_table[pos] + (1 << (dv_iweight_bits - 1))) >> dv_iweight_bits;
        block[scan_table[pos]] = level;

        UPDATE_CACHE(re, gb);
    }
    CLOSE_READER(re, gb);
    mb->pos = pos;
}

static inline void bit_copy(PutBitContext *pb, GetBitContext *gb)
{
    int bits_left = get_bits_left(gb);
    while (bits_left >= MIN_CACHE_BITS) {
        put_bits(pb, MIN_CACHE_BITS, get_bits(gb, MIN_CACHE_BITS));
        bits_left -= MIN_CACHE_BITS;
    }
    if (bits_left > 0) {
        put_bits(pb, bits_left, get_bits(gb, bits_left));
    }
}

/* mb_x and mb_y are in units of 8 pixels */
static int dv_decode_video_segment(AVCodecContext *avctx, void *arg)
{
    DVVideoContext *s = avctx->priv_data;
    DVwork_chunk *work_chunk = arg;
    int quant, dc, dct_mode, class1, j;
    int mb_index, mb_x, mb_y, last_index;
    int y_stride, linesize;
    DCTELEM *block, *block1;
    int c_offset;
    uint8_t *y_ptr;
    const uint8_t *buf_ptr;
    PutBitContext pb, vs_pb;
    GetBitContext gb;
    BlockInfo mb_data[5 * DV_MAX_BPM], *mb, *mb1;
    LOCAL_ALIGNED_16(DCTELEM, sblock, [5*DV_MAX_BPM], [64]);
    LOCAL_ALIGNED_16(uint8_t, mb_bit_buffer, [  80 + FF_INPUT_BUFFER_PADDING_SIZE]); /* allow some slack */
    LOCAL_ALIGNED_16(uint8_t, vs_bit_buffer, [5*80 + FF_INPUT_BUFFER_PADDING_SIZE]); /* allow some slack */
    const int log2_blocksize = 3;
    int is_field_mode[5];

    assert((((int)mb_bit_buffer) & 7) == 0);
    assert((((int)vs_bit_buffer) & 7) == 0);

    memset(sblock, 0, 5*DV_MAX_BPM*sizeof(*sblock));

    /* pass 1: read DC and AC coefficients in blocks */
    buf_ptr = &s->buf[work_chunk->buf_offset*80];
    block1  = &sblock[0][0];
    mb1     = mb_data;
    init_put_bits(&vs_pb, vs_bit_buffer, 5 * 80);
    for (mb_index = 0; mb_index < 5; mb_index++, mb1 += s->sys->bpm, block1 += s->sys->bpm * 64) {
        /* skip header */
        quant = buf_ptr[3] & 0x0f;
        buf_ptr += 4;
        init_put_bits(&pb, mb_bit_buffer, 80);
        mb    = mb1;
        block = block1;
        is_field_mode[mb_index] = 0;
        for (j = 0; j < s->sys->bpm; j++) {
            last_index = s->sys->block_sizes[j];
            init_get_bits(&gb, buf_ptr, last_index);

            /* get the DC */
            dc       = get_sbits(&gb, 9);
            dct_mode = get_bits1(&gb);
            class1   = get_bits(&gb, 2);
            if (DV_PROFILE_IS_HD(s->sys)) {
                mb->idct_put     = s->idct_put[0];
                mb->scan_table   = s->dv_zigzag[0];
                mb->factor_table = &s->sys->idct_factor[(j >= 4)*4*16*64 + class1*16*64 + quant*64];
                is_field_mode[mb_index] |= !j && dct_mode;
            } else {
                mb->idct_put     = s->idct_put[dct_mode && log2_blocksize == 3];
                mb->scan_table   = s->dv_zigzag[dct_mode];
                mb->factor_table = &s->sys->idct_factor[(class1 == 3)*2*22*64 + dct_mode*22*64 +
                                                        (quant + ff_dv_quant_offset[class1])*64];
            }
            dc = dc << 2;
            /* convert to unsigned because 128 is not added in the
               standard IDCT */
            dc += 1024;
            block[0] = dc;
            buf_ptr += last_index >> 3;
            mb->pos               = 0;
            mb->partial_bit_count = 0;

            av_dlog(avctx, "MB block: %d, %d ", mb_index, j);
            dv_decode_ac(&gb, mb, block);

            /* write the remaining bits in a new buffer only if the
               block is finished */
            if (mb->pos >= 64)
                bit_copy(&pb, &gb);

            block += 64;
            mb++;
        }

        /* pass 2: we can do it just after */
        av_dlog(avctx, "***pass 2 size=%d MB#=%d\n", put_bits_count(&pb), mb_index);
        block = block1;
        mb    = mb1;
        init_get_bits(&gb, mb_bit_buffer, put_bits_count(&pb));
        put_bits32(&pb, 0); // padding must be zeroed
        flush_put_bits(&pb);
        for (j = 0; j < s->sys->bpm; j++, block += 64, mb++) {
            if (mb->pos < 64 && get_bits_left(&gb) > 0) {
                dv_decode_ac(&gb, mb, block);
                /* if still not finished, no need to parse other blocks */
                if (mb->pos < 64)
                    break;
            }
        }
        /* all blocks are finished, so the extra bytes can be used at
           the video segment level */
        if (j >= s->sys->bpm)
            bit_copy(&vs_pb, &gb);
    }

    /* we need a pass over the whole video segment */
    av_dlog(avctx, "***pass 3 size=%d\n", put_bits_count(&vs_pb));
    block = &sblock[0][0];
    mb    = mb_data;
    init_get_bits(&gb, vs_bit_buffer, put_bits_count(&vs_pb));
    put_bits32(&vs_pb, 0); // padding must be zeroed
    flush_put_bits(&vs_pb);
    for (mb_index = 0; mb_index < 5; mb_index++) {
        for (j = 0; j < s->sys->bpm; j++) {
            if (mb->pos < 64) {
                av_dlog(avctx, "start %d:%d\n", mb_index, j);
                dv_decode_ac(&gb, mb, block);
            }
            if (mb->pos >= 64 && mb->pos < 127)
                av_log(avctx, AV_LOG_ERROR, "AC EOB marker is absent pos=%d\n", mb->pos);
            block += 64;
            mb++;
        }
    }

    /* compute idct and place blocks */
    block = &sblock[0][0];
    mb    = mb_data;
    for (mb_index = 0; mb_index < 5; mb_index++) {
        dv_calculate_mb_xy(s, work_chunk, mb_index, &mb_x, &mb_y);

        /* idct_put'ting luminance */
        if ((s->sys->pix_fmt == AV_PIX_FMT_YUV420P) ||
            (s->sys->pix_fmt == AV_PIX_FMT_YUV411P && mb_x >= (704 / 8)) ||
            (s->sys->height >= 720 && mb_y != 134)) {
            y_stride = (s->picture.linesize[0] << ((!is_field_mode[mb_index]) * log2_blocksize));
        } else {
            y_stride = (2 << log2_blocksize);
        }
        y_ptr = s->picture.data[0] + ((mb_y * s->picture.linesize[0] + mb_x) << log2_blocksize);
        linesize = s->picture.linesize[0] << is_field_mode[mb_index];
        mb[0]    .idct_put(y_ptr                                   , linesize, block + 0*64);
        if (s->sys->video_stype == 4) { /* SD 422 */
            mb[2].idct_put(y_ptr + (1 << log2_blocksize)           , linesize, block + 2*64);
        } else {
            mb[1].idct_put(y_ptr + (1 << log2_blocksize)           , linesize, block + 1*64);
            mb[2].idct_put(y_ptr                         + y_stride, linesize, block + 2*64);
            mb[3].idct_put(y_ptr + (1 << log2_blocksize) + y_stride, linesize, block + 3*64);
        }
        mb += 4;
        block += 4*64;

        /* idct_put'ting chrominance */
        c_offset = (((mb_y >>  (s->sys->pix_fmt == AV_PIX_FMT_YUV420P)) * s->picture.linesize[1] +
                     (mb_x >> ((s->sys->pix_fmt == AV_PIX_FMT_YUV411P) ? 2 : 1))) << log2_blocksize);
        for (j = 2; j; j--) {
            uint8_t *c_ptr = s->picture.data[j] + c_offset;
            if (s->sys->pix_fmt == AV_PIX_FMT_YUV411P && mb_x >= (704 / 8)) {
                  uint64_t aligned_pixels[64/8];
                  uint8_t *pixels = (uint8_t*)aligned_pixels;
                  uint8_t *c_ptr1, *ptr1;
                  int x, y;
                  mb->idct_put(pixels, 8, block);
                  for (y = 0; y < (1 << log2_blocksize); y++, c_ptr += s->picture.linesize[j], pixels += 8) {
                      ptr1   = pixels + (1 << (log2_blocksize - 1));
                      c_ptr1 = c_ptr + (s->picture.linesize[j] << log2_blocksize);
                      for (x = 0; x < (1 << (log2_blocksize - 1)); x++) {
                          c_ptr[x]  = pixels[x];
                          c_ptr1[x] = ptr1[x];
                      }
                  }
                  block += 64; mb++;
            } else {
                  y_stride = (mb_y == 134) ? (1 << log2_blocksize) :
                                             s->picture.linesize[j] << ((!is_field_mode[mb_index]) * log2_blocksize);
                  linesize = s->picture.linesize[j] << is_field_mode[mb_index];
                  (mb++)->    idct_put(c_ptr           , linesize, block); block += 64;
                  if (s->sys->bpm == 8) {
                      (mb++)->idct_put(c_ptr + y_stride, linesize, block); block += 64;
                  }
            }
        }
    }
    return 0;
}

/* NOTE: exactly one frame must be given (120000 bytes for NTSC,
   144000 bytes for PAL - or twice those for 50Mbps) */
static int dvvideo_decode_frame(AVCodecContext *avctx,
                                 void *data, int *got_frame,
                                 AVPacket *avpkt)
{
    uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    DVVideoContext *s = avctx->priv_data;
    const uint8_t* vsc_pack;
    int apt, is16_9;

    s->sys = avpriv_dv_frame_profile(s->sys, buf, buf_size);
    if (!s->sys || buf_size < s->sys->frame_size || ff_dv_init_dynamic_tables(s->sys)) {
        av_log(avctx, AV_LOG_ERROR, "could not find dv frame profile\n");
        return -1; /* NOTE: we only accept several full frames */
    }

    if (s->picture.data[0])
        avctx->release_buffer(avctx, &s->picture);

    s->picture.reference = 0;
    s->picture.key_frame = 1;
    s->picture.pict_type = AV_PICTURE_TYPE_I;
    avctx->pix_fmt   = s->sys->pix_fmt;
    avctx->time_base = s->sys->time_base;
    avcodec_set_dimensions(avctx, s->sys->width, s->sys->height);
    if (ff_get_buffer(avctx, &s->picture) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return -1;
    }
    s->picture.interlaced_frame = 1;
    s->picture.top_field_first  = 0;

    s->buf = buf;
    avctx->execute(avctx, dv_decode_video_segment, s->sys->work_chunks, NULL,
                   dv_work_pool_size(s->sys), sizeof(DVwork_chunk));

    emms_c();

    /* return image */
    *got_frame = 1;
    *(AVFrame*)data = s->picture;

    /* Determine the codec's sample_aspect ratio from the packet */
    vsc_pack = buf + 80*5 + 48 + 5;
    if ( *vsc_pack == dv_video_control ) {
        apt = buf[4] & 0x07;
        is16_9 = (vsc_pack && ((vsc_pack[2] & 0x07) == 0x02 || (!apt && (vsc_pack[2] & 0x07) == 0x07)));
        avctx->sample_aspect_ratio = s->sys->sar[is16_9];
    }

    return s->sys->frame_size;
}

static int dvvideo_close(AVCodecContext *c)
{
    DVVideoContext *s = c->priv_data;

    if (s->picture.data[0])
        c->release_buffer(c, &s->picture);

    return 0;
}

AVCodec ff_dvvideo_decoder = {
    .name           = "dvvideo",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_DVVIDEO,
    .priv_data_size = sizeof(DVVideoContext),
    .init           = ff_dvvideo_init,
    .close          = dvvideo_close,
    .decode         = dvvideo_decode_frame,
    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_SLICE_THREADS,
    .long_name      = NULL_IF_CONFIG_SMALL("DV (Digital Video)"),
};