aboutsummaryrefslogtreecommitdiffstats
path: root/libavformat/av1dec.c
blob: 8b74fa1af8f17a05ea14ff9bd4a82c3db7131bfa (plain) (blame)
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
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
/*
 * AV1 Annex B demuxer
 * Copyright (c) 2019 James Almer <jamrial@gmail.com>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg 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.
 *
 * FFmpeg 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 FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "config_components.h"

#include "libavutil/common.h"
#include "libavutil/opt.h"
#include "libavcodec/av1_parse.h"
#include "libavcodec/bsf.h"
#include "avformat.h"
#include "avio_internal.h"
#include "internal.h"

typedef struct AV1DemuxContext {
    const AVClass *class;
    AVBSFContext *bsf;
    AVRational framerate;
    uint32_t temporal_unit_size;
    uint32_t frame_unit_size;
} AV1DemuxContext;

//return < 0 if we need more data
static int get_score(int type, int *seq)
{
    switch (type) {
    case AV1_OBU_SEQUENCE_HEADER:
        *seq = 1;
        return -1;
    case AV1_OBU_FRAME:
    case AV1_OBU_FRAME_HEADER:
        return *seq ? AVPROBE_SCORE_EXTENSION + 1 : 0;
    case AV1_OBU_METADATA:
    case AV1_OBU_PADDING:
        return -1;
    default:
        break;
    }
    return 0;
}

static int av1_read_header(AVFormatContext *s)
{
    AV1DemuxContext *const c = s->priv_data;
    const AVBitStreamFilter *filter = av_bsf_get_by_name("av1_frame_merge");
    AVStream *st;
    FFStream *sti;
    int ret;

    if (!filter) {
        av_log(s, AV_LOG_ERROR, "av1_frame_merge bitstream filter "
               "not found. This is a bug, please report it.\n");
        return AVERROR_BUG;
    }

    st = avformat_new_stream(s, NULL);
    if (!st)
        return AVERROR(ENOMEM);
    sti = ffstream(st);

    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
    st->codecpar->codec_id = AV_CODEC_ID_AV1;
    sti->need_parsing = AVSTREAM_PARSE_HEADERS;

    st->avg_frame_rate = c->framerate;
    // taken from rawvideo demuxers
    avpriv_set_pts_info(st, 64, 1, 1200000);

    ret = av_bsf_alloc(filter, &c->bsf);
    if (ret < 0)
        return ret;

    ret = avcodec_parameters_copy(c->bsf->par_in, st->codecpar);
    if (ret < 0)
        return ret;

    ret = av_bsf_init(c->bsf);
    if (ret < 0)
        return ret;

    return 0;
}

static int av1_read_close(AVFormatContext *s)
{
    AV1DemuxContext *const c = s->priv_data;

    av_bsf_free(&c->bsf);
    return 0;
}

#define DEC AV_OPT_FLAG_DECODING_PARAM
#define OFFSET(x) offsetof(AV1DemuxContext, x)
static const AVOption av1_options[] = {
    { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, INT_MAX, DEC},
    { NULL },
};
#undef OFFSET

static const AVClass av1_demuxer_class = {
    .class_name = "AV1 Annex B/low overhead OBU demuxer",
    .option     = av1_options,
    .version    = LIBAVUTIL_VERSION_INT,
};

#if CONFIG_AV1_DEMUXER

static int leb(AVIOContext *pb, uint32_t *len, int eof) {
    int more, i = 0;
    *len = 0;
    do {
        unsigned bits;
        int byte = avio_r8(pb);
        if (pb->error)
            return pb->error;
        if (pb->eof_reached)
            return (eof && !i) ? AVERROR_EOF : AVERROR_INVALIDDATA;
        more = byte & 0x80;
        bits = byte & 0x7f;
        if (i <= 3 || (i == 4 && bits < (1 << 4)))
            *len |= bits << (i * 7);
        else if (bits)
            return AVERROR_INVALIDDATA;
        if (++i == 8 && more)
            return AVERROR_INVALIDDATA;
    } while (more);
    return i;
}

static int read_obu(const uint8_t *buf, int size, int64_t *obu_size, int *type)
{
    int start_pos, temporal_id, spatial_id;
    int len;

    len = parse_obu_header(buf, size, obu_size, &start_pos,
                           type, &temporal_id, &spatial_id);
    if (len < 0)
        return len;

    return 0;
}

static int annexb_probe(const AVProbeData *p)
{
    FFIOContext ctx;
    AVIOContext *const pb = &ctx.pub;
    int64_t obu_size;
    uint32_t temporal_unit_size, frame_unit_size, obu_unit_size;
    int seq = 0;
    int ret, type, cnt = 0;

    ffio_init_read_context(&ctx, p->buf, p->buf_size);

    ret = leb(pb, &temporal_unit_size, 1);
    if (ret < 0)
        return 0;
    cnt += ret;
    ret = leb(pb, &frame_unit_size, 0);
    if (ret < 0 || ((int64_t)frame_unit_size + ret) > temporal_unit_size)
        return 0;
    cnt += ret;
    ret = leb(pb, &obu_unit_size, 0);
    if (ret < 0 || ((int64_t)obu_unit_size + ret) >= frame_unit_size)
        return 0;
    cnt += ret;

    frame_unit_size -= obu_unit_size + ret;

    avio_skip(pb, obu_unit_size);
    if (pb->eof_reached || pb->error)
        return 0;

    // Check that the first OBU is a Temporal Delimiter.
    ret = read_obu(p->buf + cnt, FFMIN(p->buf_size - cnt, obu_unit_size), &obu_size, &type);
    if (ret < 0 || type != AV1_OBU_TEMPORAL_DELIMITER || obu_size > 0)
        return 0;
    cnt += obu_unit_size;

    do {
        ret = leb(pb, &obu_unit_size, 0);
        if (ret < 0 || ((int64_t)obu_unit_size + ret) > frame_unit_size)
            return 0;
        cnt += ret;

        avio_skip(pb, obu_unit_size);
        if (pb->eof_reached || pb->error)
            return 0;

        ret = read_obu(p->buf + cnt, FFMIN(p->buf_size - cnt, obu_unit_size), &obu_size, &type);
        if (ret < 0)
            return 0;
        cnt += obu_unit_size;

        ret = get_score(type, &seq);
        if (ret >= 0)
            return ret;

        frame_unit_size -= obu_unit_size + ret;
    } while (frame_unit_size);

    return 0;
}

static int annexb_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    AV1DemuxContext *const c = s->priv_data;
    uint32_t obu_unit_size;
    int ret, len;

retry:
    if (avio_feof(s->pb)) {
        if (c->temporal_unit_size || c->frame_unit_size)
            return AVERROR_INVALIDDATA;
        goto end;
    }

    if (!c->temporal_unit_size) {
        len = leb(s->pb, &c->temporal_unit_size, 1);
        if (len == AVERROR_EOF) goto end;
        else if (len < 0) return len;
    }

    if (!c->frame_unit_size) {
        len = leb(s->pb, &c->frame_unit_size, 0);
        if (len < 0)
            return len;
        if (((int64_t)c->frame_unit_size + len) > c->temporal_unit_size)
            return AVERROR_INVALIDDATA;
        c->temporal_unit_size -= len;
    }

    len = leb(s->pb, &obu_unit_size, 0);
    if (len < 0)
        return len;
    if (((int64_t)obu_unit_size + len) > c->frame_unit_size)
        return AVERROR_INVALIDDATA;

    ret = av_get_packet(s->pb, pkt, obu_unit_size);
    if (ret < 0)
        return ret;
    if (ret != obu_unit_size)
        return AVERROR_INVALIDDATA;

    c->temporal_unit_size -= obu_unit_size + len;
    c->frame_unit_size -= obu_unit_size + len;

end:
    ret = av_bsf_send_packet(c->bsf, pkt);
    if (ret < 0) {
        av_log(s, AV_LOG_ERROR, "Failed to send packet to "
                                "av1_frame_merge filter\n");
        return ret;
    }

    ret = av_bsf_receive_packet(c->bsf, pkt);
    if (ret < 0 && ret != AVERROR(EAGAIN) && ret != AVERROR_EOF)
        av_log(s, AV_LOG_ERROR, "av1_frame_merge filter failed to "
                                "send output packet\n");

    if (ret == AVERROR(EAGAIN))
        goto retry;

    return ret;
}

const AVInputFormat ff_av1_demuxer = {
    .name           = "av1",
    .long_name      = NULL_IF_CONFIG_SMALL("AV1 Annex B"),
    .priv_data_size = sizeof(AV1DemuxContext),
    .flags_internal = FF_FMT_INIT_CLEANUP,
    .read_probe     = annexb_probe,
    .read_header    = av1_read_header,
    .read_packet    = annexb_read_packet,
    .read_close     = av1_read_close,
    .extensions     = "obu",
    .flags          = AVFMT_GENERIC_INDEX | AVFMT_NOTIMESTAMPS,
    .priv_class     = &av1_demuxer_class,
};
#endif

#if CONFIG_OBU_DEMUXER
//For low overhead obu, we can't foresee the obu size before we parsed the header.
//So, we can't use parse_obu_header here, since it will check size <= buf_size
//see c27c7b49dc for more details
static int read_obu_with_size(const uint8_t *buf, int buf_size, int64_t *obu_size, int *type)
{
    GetBitContext gb;
    int ret, extension_flag, start_pos;
    int64_t size;

    ret = init_get_bits8(&gb, buf, FFMIN(buf_size, MAX_OBU_HEADER_SIZE));
    if (ret < 0)
        return ret;

    if (get_bits1(&gb) != 0) // obu_forbidden_bit
        return AVERROR_INVALIDDATA;

    *type      = get_bits(&gb, 4);
    extension_flag = get_bits1(&gb);
    if (!get_bits1(&gb))    // has_size_flag
        return AVERROR_INVALIDDATA;
    skip_bits1(&gb);        // obu_reserved_1bit

    if (extension_flag) {
        get_bits(&gb, 3);   // temporal_id
        get_bits(&gb, 2);   // spatial_id
        skip_bits(&gb, 3);  // extension_header_reserved_3bits
    }

    *obu_size  = leb128(&gb);
    if (*obu_size > INT_MAX)
        return AVERROR_INVALIDDATA;

    if (get_bits_left(&gb) < 0)
        return AVERROR_INVALIDDATA;

    start_pos = get_bits_count(&gb) / 8;

    size = *obu_size + start_pos;
    if (size > INT_MAX)
        return AVERROR_INVALIDDATA;
    return size;
}

static int obu_probe(const AVProbeData *p)
{
    int64_t obu_size;
    int seq = 0;
    int ret, type, cnt;

    // Check that the first OBU is a Temporal Delimiter.
    cnt = read_obu_with_size(p->buf, p->buf_size, &obu_size, &type);
    if (cnt < 0 || type != AV1_OBU_TEMPORAL_DELIMITER || obu_size != 0)
        return 0;

    while (1) {
        ret = read_obu_with_size(p->buf + cnt, p->buf_size - cnt, &obu_size, &type);
        if (ret < 0 || obu_size <= 0)
            return 0;
        cnt += FFMIN(ret, p->buf_size - cnt);

        ret = get_score(type, &seq);
        if (ret >= 0)
            return ret;
    }
    return 0;
}

static int obu_get_packet(AVFormatContext *s, AVPacket *pkt)
{
    AV1DemuxContext *const c = s->priv_data;
    uint8_t header[MAX_OBU_HEADER_SIZE + AV_INPUT_BUFFER_PADDING_SIZE];
    int64_t obu_size;
    int size;
    int ret, len, type;

    if ((ret = ffio_ensure_seekback(s->pb, MAX_OBU_HEADER_SIZE)) < 0)
        return ret;
    size = avio_read(s->pb, header, MAX_OBU_HEADER_SIZE);
    if (size < 0)
        return size;

    len = read_obu_with_size(header, size, &obu_size, &type);
    if (len < 0) {
        av_log(c, AV_LOG_ERROR, "Failed to read obu\n");
        return len;
    }
    avio_seek(s->pb, -size, SEEK_CUR);

    ret = av_get_packet(s->pb, pkt, len);
    if (ret != len) {
        av_log(c, AV_LOG_ERROR, "Failed to get packet for obu\n");
        return ret < 0 ? ret : AVERROR_INVALIDDATA;
    }
    return 0;
}

static int obu_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    AV1DemuxContext *const c = s->priv_data;
    int ret;

    if (s->io_repositioned) {
        av_bsf_flush(c->bsf);
        s->io_repositioned = 0;
    }
    while (1) {
        ret = obu_get_packet(s, pkt);
        /* In case of AVERROR_EOF we need to flush the BSF. Conveniently
         * obu_get_packet() returns a blank pkt in this case which
         * can be used to signal that the BSF should be flushed. */
        if (ret < 0 && ret != AVERROR_EOF)
            return ret;
        ret = av_bsf_send_packet(c->bsf, pkt);
        if (ret < 0) {
            av_log(s, AV_LOG_ERROR, "Failed to send packet to "
                                    "av1_frame_merge filter\n");
            return ret;
        }
        ret = av_bsf_receive_packet(c->bsf, pkt);
        if (ret < 0 && ret != AVERROR(EAGAIN) && ret != AVERROR_EOF)
            av_log(s, AV_LOG_ERROR, "av1_frame_merge filter failed to "
                                    "send output packet\n");
        if (ret != AVERROR(EAGAIN))
            break;
    }

    return ret;
}

const AVInputFormat ff_obu_demuxer = {
    .name           = "obu",
    .long_name      = NULL_IF_CONFIG_SMALL("AV1 low overhead OBU"),
    .priv_data_size = sizeof(AV1DemuxContext),
    .flags_internal = FF_FMT_INIT_CLEANUP,
    .read_probe     = obu_probe,
    .read_header    = av1_read_header,
    .read_packet    = obu_read_packet,
    .read_close     = av1_read_close,
    .extensions     = "obu",
    .flags          = AVFMT_GENERIC_INDEX | AVFMT_NO_BYTE_SEEK | AVFMT_NOTIMESTAMPS,
    .priv_class     = &av1_demuxer_class,
};
#endif