GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/cbs_mpeg2.c Lines: 95 115 82.6 %
Date: 2020-11-29 04:57:13 Branches: 52 80 65.0 %

Line Branch Exec Source
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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
17
 */
18
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#include "libavutil/avassert.h"
20
21
#include "cbs.h"
22
#include "cbs_internal.h"
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#include "cbs_mpeg2.h"
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#include "internal.h"
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26
27
#define HEADER(name) do { \
28
        ff_cbs_trace_header(ctx, name); \
29
    } while (0)
30
31
#define CHECK(call) do { \
32
        err = (call); \
33
        if (err < 0) \
34
            return err; \
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    } while (0)
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#define FUNC_NAME(rw, codec, name) cbs_ ## codec ## _ ## rw ## _ ## name
38
#define FUNC_MPEG2(rw, name) FUNC_NAME(rw, mpeg2, name)
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#define FUNC(name) FUNC_MPEG2(READWRITE, name)
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#define SUBSCRIPTS(subs, ...) (subs > 0 ? ((int[subs + 1]){ subs, __VA_ARGS__ }) : NULL)
42
43
#define ui(width, name) \
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        xui(width, name, current->name, 0, MAX_UINT_BITS(width), 0, )
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#define uir(width, name) \
46
        xui(width, name, current->name, 1, MAX_UINT_BITS(width), 0, )
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#define uis(width, name, subs, ...) \
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        xui(width, name, current->name, 0, MAX_UINT_BITS(width), subs, __VA_ARGS__)
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#define uirs(width, name, subs, ...) \
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        xui(width, name, current->name, 1, MAX_UINT_BITS(width), subs, __VA_ARGS__)
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#define xui(width, name, var, range_min, range_max, subs, ...) \
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        xuia(width, #name, var, range_min, range_max, subs, __VA_ARGS__)
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#define sis(width, name, subs, ...) \
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        xsi(width, name, current->name, subs, __VA_ARGS__)
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#define marker_bit() \
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        bit("marker_bit", 1)
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#define bit(string, value) do { \
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        av_unused uint32_t bit = value; \
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        xuia(1, string, bit, value, value, 0, ); \
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    } while (0)
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#define READ
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#define READWRITE read
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#define RWContext GetBitContext
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#define xuia(width, string, var, range_min, range_max, subs, ...) do { \
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        uint32_t value; \
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        CHECK(ff_cbs_read_unsigned(ctx, rw, width, string, \
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                                   SUBSCRIPTS(subs, __VA_ARGS__), \
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                                   &value, range_min, range_max)); \
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        var = value; \
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    } while (0)
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#define xsi(width, name, var, subs, ...) do { \
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        int32_t value; \
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        CHECK(ff_cbs_read_signed(ctx, rw, width, #name, \
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                                 SUBSCRIPTS(subs, __VA_ARGS__), &value, \
80
                                 MIN_INT_BITS(width), \
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                                 MAX_INT_BITS(width))); \
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        var = value; \
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    } while (0)
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#define nextbits(width, compare, var) \
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    (get_bits_left(rw) >= width && \
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     (var = show_bits(rw, width)) == (compare))
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#define infer(name, value) do { \
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        current->name = value; \
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    } while (0)
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#include "cbs_mpeg2_syntax_template.c"
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#undef READ
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#undef READWRITE
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#undef RWContext
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#undef xuia
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#undef xsi
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#undef nextbits
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#undef infer
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#define WRITE
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#define READWRITE write
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#define RWContext PutBitContext
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#define xuia(width, string, var, range_min, range_max, subs, ...) do { \
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        CHECK(ff_cbs_write_unsigned(ctx, rw, width, string, \
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                                    SUBSCRIPTS(subs, __VA_ARGS__), \
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                                    var, range_min, range_max)); \
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    } while (0)
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#define xsi(width, name, var, subs, ...) do { \
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        CHECK(ff_cbs_write_signed(ctx, rw, width, #name, \
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                                  SUBSCRIPTS(subs, __VA_ARGS__), var, \
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                                  MIN_INT_BITS(width), \
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                                  MAX_INT_BITS(width))); \
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    } while (0)
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121
#define nextbits(width, compare, var) (var)
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#define infer(name, value) do { \
124
        if (current->name != (value)) { \
125
            av_log(ctx->log_ctx, AV_LOG_WARNING, "Warning: " \
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                   "%s does not match inferred value: " \
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                   "%"PRId64", but should be %"PRId64".\n", \
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                   #name, (int64_t)current->name, (int64_t)(value)); \
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        } \
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    } while (0)
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#include "cbs_mpeg2_syntax_template.c"
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#undef WRITE
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#undef READWRITE
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#undef RWContext
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#undef xuia
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#undef xsi
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#undef nextbits
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#undef infer
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static int cbs_mpeg2_split_fragment(CodedBitstreamContext *ctx,
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                                    CodedBitstreamFragment *frag,
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                                    int header)
146
{
147
    const uint8_t *start, *end;
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    CodedBitstreamUnitType unit_type;
149
18
    uint32_t start_code = -1;
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    size_t unit_size;
151
18
    int err, i, final = 0;
152
153
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    start = avpriv_find_start_code(frag->data, frag->data + frag->data_size,
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                                   &start_code);
155
18
    if (start_code >> 8 != 0x000001) {
156
        // No start code found.
157
        return AVERROR_INVALIDDATA;
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    }
159
160
18
    for (i = 0;; i++) {
161
8843
        unit_type = start_code & 0xff;
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8843
        if (start == frag->data + frag->data_size) {
164
            // The last four bytes form a start code which constitutes
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            // a unit of its own.  In this situation avpriv_find_start_code
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            // won't modify start_code at all so modify start_code so that
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            // the next unit will be treated as the last unit.
168
3
            start_code = 0;
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        }
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8843
        end = avpriv_find_start_code(start--, frag->data + frag->data_size,
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                                     &start_code);
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        // start points to the byte containing the start_code_identifier
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        // (may be the last byte of fragment->data); end points to the byte
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        // following the byte containing the start code identifier (or to
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        // the end of fragment->data).
178
8843
        if (start_code >> 8 == 0x000001) {
179
            // Unit runs from start to the beginning of the start code
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            // pointed to by end (including any padding zeroes).
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8825
            unit_size = (end - 4) - start;
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        } else {
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           // We didn't find a start code, so this is the final unit.
184
18
           unit_size = end - start;
185
18
           final     = 1;
186
        }
187
188
8843
        err = ff_cbs_insert_unit_data(frag, i, unit_type, (uint8_t*)start,
189
                                      unit_size, frag->data_ref);
190
8843
        if (err < 0)
191
            return err;
192
193
8843
        if (final)
194
18
            break;
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196
8825
        start = end;
197
    }
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199
18
    return 0;
200
}
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8843
static int cbs_mpeg2_read_unit(CodedBitstreamContext *ctx,
203
                               CodedBitstreamUnit *unit)
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{
205
    GetBitContext gbc;
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    int err;
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8843
    err = init_get_bits(&gbc, unit->data, 8 * unit->data_size);
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8843
    if (err < 0)
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        return err;
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212
8843
    err = ff_cbs_alloc_unit_content2(ctx, unit);
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8843
    if (err < 0)
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        return err;
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216

8843
    if (MPEG2_START_IS_SLICE(unit->type)) {
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8746
        MPEG2RawSlice *slice = unit->content;
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        int pos, len;
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220
8746
        err = cbs_mpeg2_read_slice_header(ctx, &gbc, &slice->header);
221
8746
        if (err < 0)
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            return err;
223
224
8746
        if (!get_bits_left(&gbc))
225
            return AVERROR_INVALIDDATA;
226
227
8746
        pos = get_bits_count(&gbc);
228
8746
        len = unit->data_size;
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230
8746
        slice->data_size = len - pos / 8;
231
8746
        slice->data_ref  = av_buffer_ref(unit->data_ref);
232
8746
        if (!slice->data_ref)
233
            return AVERROR(ENOMEM);
234
8746
        slice->data = unit->data + pos / 8;
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8746
        slice->data_bit_start = pos % 8;
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238
    } else {
239

97
        switch (unit->type) {
240
#define START(start_code, type, read_func, free_func) \
241
        case start_code: \
242
            { \
243
                type *header = unit->content; \
244
                err = cbs_mpeg2_read_ ## read_func(ctx, &gbc, header); \
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                if (err < 0) \
246
                    return err; \
247
            } \
248
            break;
249
19
            START(MPEG2_START_PICTURE,   MPEG2RawPictureHeader,
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                  picture_header,           &cbs_mpeg2_free_picture_header);
251
14
            START(MPEG2_START_USER_DATA, MPEG2RawUserData,
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                  user_data,                &cbs_mpeg2_free_user_data);
253
6
            START(MPEG2_START_SEQUENCE_HEADER, MPEG2RawSequenceHeader,
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                  sequence_header,          NULL);
255
53
            START(MPEG2_START_EXTENSION, MPEG2RawExtensionData,
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                  extension_data,           NULL);
257
2
            START(MPEG2_START_GROUP,     MPEG2RawGroupOfPicturesHeader,
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                  group_of_pictures_header, NULL);
259
3
            START(MPEG2_START_SEQUENCE_END, MPEG2RawSequenceEnd,
260
                  sequence_end,             NULL);
261
#undef START
262
        default:
263
            return AVERROR(ENOSYS);
264
        }
265
    }
266
267
8843
    return 0;
268
}
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270
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static int cbs_mpeg2_write_header(CodedBitstreamContext *ctx,
271
                                  CodedBitstreamUnit *unit,
272
                                  PutBitContext *pbc)
273
{
274
    int err;
275
276

97
    switch (unit->type) {
277
#define START(start_code, type, func) \
278
    case start_code: \
279
        err = cbs_mpeg2_write_ ## func(ctx, pbc, unit->content); \
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        break;
281
19
        START(MPEG2_START_PICTURE,         MPEG2RawPictureHeader,  picture_header);
282
14
        START(MPEG2_START_USER_DATA,       MPEG2RawUserData,       user_data);
283
6
        START(MPEG2_START_SEQUENCE_HEADER, MPEG2RawSequenceHeader, sequence_header);
284
53
        START(MPEG2_START_EXTENSION,       MPEG2RawExtensionData,  extension_data);
285
2
        START(MPEG2_START_GROUP,           MPEG2RawGroupOfPicturesHeader,
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                                                         group_of_pictures_header);
287
3
        START(MPEG2_START_SEQUENCE_END,    MPEG2RawSequenceEnd,    sequence_end);
288
#undef START
289
    default:
290
        av_log(ctx->log_ctx, AV_LOG_ERROR, "Write unimplemented for start "
291
               "code %02"PRIx32".\n", unit->type);
292
        return AVERROR_PATCHWELCOME;
293
    }
294
295
97
    return err;
296
}
297
298
8746
static int cbs_mpeg2_write_slice(CodedBitstreamContext *ctx,
299
                                 CodedBitstreamUnit *unit,
300
                                 PutBitContext *pbc)
301
{
302
8746
    MPEG2RawSlice *slice = unit->content;
303
    int err;
304
305
8746
    err = cbs_mpeg2_write_slice_header(ctx, pbc, &slice->header);
306
8746
    if (err < 0)
307
        return err;
308
309
8746
    if (slice->data) {
310
8746
        size_t rest = slice->data_size - (slice->data_bit_start + 7) / 8;
311
8746
        uint8_t *pos = slice->data + slice->data_bit_start / 8;
312
313

8746
        av_assert0(slice->data_bit_start >= 0 &&
314
                   slice->data_size > slice->data_bit_start / 8);
315
316
8746
        if (slice->data_size * 8 + 8 > put_bits_left(pbc))
317
            return AVERROR(ENOSPC);
318
319
        // First copy the remaining bits of the first byte
320
8746
        if (slice->data_bit_start % 8)
321
8746
            put_bits(pbc, 8 - slice->data_bit_start % 8,
322
8746
                     *pos++ & MAX_UINT_BITS(8 - slice->data_bit_start % 8));
323
324
8746
        if (put_bits_count(pbc) % 8 == 0) {
325
            // If the writer is aligned at this point,
326
            // memcpy can be used to improve performance.
327
            // This is the normal case.
328
8746
            flush_put_bits(pbc);
329
8746
            memcpy(put_bits_ptr(pbc), pos, rest);
330
8746
            skip_put_bytes(pbc, rest);
331
        } else {
332
            // If not, we have to copy manually:
333
            for (; rest > 3; rest -= 4, pos += 4)
334
                put_bits32(pbc, AV_RB32(pos));
335
336
            for (; rest; rest--, pos++)
337
                put_bits(pbc, 8, *pos);
338
339
            // Align with zeros
340
            put_bits(pbc, 8 - put_bits_count(pbc) % 8, 0);
341
        }
342
    }
343
344
8746
    return 0;
345
}
346
347
8843
static int cbs_mpeg2_write_unit(CodedBitstreamContext *ctx,
348
                                CodedBitstreamUnit *unit,
349
                                PutBitContext *pbc)
350
{
351

8843
    if (MPEG2_START_IS_SLICE(unit->type))
352
8746
        return cbs_mpeg2_write_slice (ctx, unit, pbc);
353
    else
354
97
        return cbs_mpeg2_write_header(ctx, unit, pbc);
355
}
356
357
18
static int cbs_mpeg2_assemble_fragment(CodedBitstreamContext *ctx,
358
                                       CodedBitstreamFragment *frag)
359
{
360
    uint8_t *data;
361
    size_t size, dp;
362
    int i;
363
364
18
    size = 0;
365
8861
    for (i = 0; i < frag->nb_units; i++)
366
8843
        size += 3 + frag->units[i].data_size;
367
368
18
    frag->data_ref = av_buffer_alloc(size + AV_INPUT_BUFFER_PADDING_SIZE);
369
18
    if (!frag->data_ref)
370
        return AVERROR(ENOMEM);
371
18
    data = frag->data_ref->data;
372
373
18
    dp = 0;
374
8861
    for (i = 0; i < frag->nb_units; i++) {
375
8843
        CodedBitstreamUnit *unit = &frag->units[i];
376
377
8843
        data[dp++] = 0;
378
8843
        data[dp++] = 0;
379
8843
        data[dp++] = 1;
380
381
8843
        memcpy(data + dp, unit->data, unit->data_size);
382
8843
        dp += unit->data_size;
383
    }
384
385
18
    av_assert0(dp == size);
386
387
18
    memset(data + size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
388
18
    frag->data      = data;
389
18
    frag->data_size = size;
390
391
18
    return 0;
392
}
393
394
static const CodedBitstreamUnitTypeDescriptor cbs_mpeg2_unit_types[] = {
395
    CBS_UNIT_TYPE_INTERNAL_REF(MPEG2_START_PICTURE, MPEG2RawPictureHeader,
396
                               extra_information_picture.extra_information),
397
398
    {
399
        .nb_unit_types         = CBS_UNIT_TYPE_RANGE,
400
        .unit_type_range_start = 0x01,
401
        .unit_type_range_end   = 0xaf,
402
403
        .content_type   = CBS_CONTENT_TYPE_INTERNAL_REFS,
404
        .content_size   = sizeof(MPEG2RawSlice),
405
        .nb_ref_offsets = 2,
406
        .ref_offsets    = { offsetof(MPEG2RawSlice, header.extra_information_slice.extra_information),
407
                            offsetof(MPEG2RawSlice, data) },
408
    },
409
410
    CBS_UNIT_TYPE_INTERNAL_REF(MPEG2_START_USER_DATA, MPEG2RawUserData,
411
                               user_data),
412
413
    CBS_UNIT_TYPE_POD(MPEG2_START_SEQUENCE_HEADER, MPEG2RawSequenceHeader),
414
    CBS_UNIT_TYPE_POD(MPEG2_START_EXTENSION,       MPEG2RawExtensionData),
415
    CBS_UNIT_TYPE_POD(MPEG2_START_SEQUENCE_END,    MPEG2RawSequenceEnd),
416
    CBS_UNIT_TYPE_POD(MPEG2_START_GROUP,           MPEG2RawGroupOfPicturesHeader),
417
418
    CBS_UNIT_TYPE_END_OF_LIST
419
};
420
421
const CodedBitstreamType ff_cbs_type_mpeg2 = {
422
    .codec_id          = AV_CODEC_ID_MPEG2VIDEO,
423
424
    .priv_data_size    = sizeof(CodedBitstreamMPEG2Context),
425
426
    .unit_types        = cbs_mpeg2_unit_types,
427
428
    .split_fragment    = &cbs_mpeg2_split_fragment,
429
    .read_unit         = &cbs_mpeg2_read_unit,
430
    .write_unit        = &cbs_mpeg2_write_unit,
431
    .assemble_fragment = &cbs_mpeg2_assemble_fragment,
432
};