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432 lines
14 KiB
432 lines
14 KiB
/* |
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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 "libavutil/avassert.h" |
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#include "cbs.h" |
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#include "cbs_internal.h" |
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#include "cbs_mpeg2.h" |
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#include "internal.h" |
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#define HEADER(name) do { \ |
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ff_cbs_trace_header(ctx, name); \ |
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} while (0) |
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#define CHECK(call) do { \ |
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err = (call); \ |
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if (err < 0) \ |
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return err; \ |
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} while (0) |
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#define FUNC_NAME(rw, codec, name) cbs_ ## codec ## _ ## rw ## _ ## name |
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#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) |
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#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) \ |
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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, \ |
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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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#define nextbits(width, compare, var) (var) |
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#define infer(name, value) do { \ |
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if (current->name != (value)) { \ |
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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 void cbs_mpeg2_free_picture_header(void *opaque, uint8_t *content) |
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{ |
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MPEG2RawPictureHeader *picture = (MPEG2RawPictureHeader*)content; |
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av_buffer_unref(&picture->extra_information_picture.extra_information_ref); |
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av_freep(&content); |
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} |
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static void cbs_mpeg2_free_user_data(void *opaque, uint8_t *content) |
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{ |
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MPEG2RawUserData *user = (MPEG2RawUserData*)content; |
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av_buffer_unref(&user->user_data_ref); |
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av_freep(&content); |
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} |
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static void cbs_mpeg2_free_slice(void *opaque, uint8_t *content) |
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{ |
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MPEG2RawSlice *slice = (MPEG2RawSlice*)content; |
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av_buffer_unref(&slice->header.extra_information_slice.extra_information_ref); |
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av_buffer_unref(&slice->data_ref); |
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av_freep(&content); |
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} |
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static int cbs_mpeg2_split_fragment(CodedBitstreamContext *ctx, |
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CodedBitstreamFragment *frag, |
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int header) |
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{ |
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const uint8_t *start, *end; |
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CodedBitstreamUnitType unit_type; |
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uint32_t start_code = -1; |
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size_t unit_size; |
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int err, i, final = 0; |
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start = avpriv_find_start_code(frag->data, frag->data + frag->data_size, |
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&start_code); |
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if (start_code >> 8 != 0x000001) { |
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// No start code found. |
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return AVERROR_INVALIDDATA; |
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} |
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for (i = 0;; i++) { |
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unit_type = start_code & 0xff; |
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if (start == frag->data + frag->data_size) { |
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// 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. |
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start_code = 0; |
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} |
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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). |
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if (start_code >> 8 == 0x000001) { |
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// 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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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. |
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unit_size = end - start; |
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final = 1; |
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} |
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err = ff_cbs_insert_unit_data(frag, i, unit_type, (uint8_t*)start, |
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unit_size, frag->data_ref); |
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if (err < 0) |
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return err; |
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if (final) |
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break; |
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start = end; |
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} |
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return 0; |
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} |
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static int cbs_mpeg2_read_unit(CodedBitstreamContext *ctx, |
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CodedBitstreamUnit *unit) |
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{ |
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GetBitContext gbc; |
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int err; |
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err = init_get_bits(&gbc, unit->data, 8 * unit->data_size); |
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if (err < 0) |
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return err; |
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if (MPEG2_START_IS_SLICE(unit->type)) { |
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MPEG2RawSlice *slice; |
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int pos, len; |
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err = ff_cbs_alloc_unit_content(unit, sizeof(*slice), |
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&cbs_mpeg2_free_slice); |
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if (err < 0) |
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return err; |
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slice = unit->content; |
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err = cbs_mpeg2_read_slice_header(ctx, &gbc, &slice->header); |
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if (err < 0) |
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return err; |
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if (!get_bits_left(&gbc)) |
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return AVERROR_INVALIDDATA; |
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pos = get_bits_count(&gbc); |
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len = unit->data_size; |
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slice->data_size = len - pos / 8; |
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slice->data_ref = av_buffer_ref(unit->data_ref); |
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if (!slice->data_ref) |
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return AVERROR(ENOMEM); |
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slice->data = unit->data + pos / 8; |
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slice->data_bit_start = pos % 8; |
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} else { |
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switch (unit->type) { |
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#define START(start_code, type, read_func, free_func) \ |
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case start_code: \ |
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{ \ |
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type *header; \ |
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err = ff_cbs_alloc_unit_content(unit, \ |
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sizeof(*header), free_func); \ |
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if (err < 0) \ |
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return err; \ |
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header = unit->content; \ |
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err = cbs_mpeg2_read_ ## read_func(ctx, &gbc, header); \ |
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if (err < 0) \ |
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return err; \ |
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} \ |
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break; |
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START(MPEG2_START_PICTURE, MPEG2RawPictureHeader, |
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picture_header, &cbs_mpeg2_free_picture_header); |
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START(MPEG2_START_USER_DATA, MPEG2RawUserData, |
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user_data, &cbs_mpeg2_free_user_data); |
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START(MPEG2_START_SEQUENCE_HEADER, MPEG2RawSequenceHeader, |
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sequence_header, NULL); |
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START(MPEG2_START_EXTENSION, MPEG2RawExtensionData, |
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extension_data, NULL); |
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START(MPEG2_START_GROUP, MPEG2RawGroupOfPicturesHeader, |
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group_of_pictures_header, NULL); |
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START(MPEG2_START_SEQUENCE_END, MPEG2RawSequenceEnd, |
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sequence_end, NULL); |
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#undef START |
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default: |
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return AVERROR(ENOSYS); |
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} |
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} |
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return 0; |
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} |
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static int cbs_mpeg2_write_header(CodedBitstreamContext *ctx, |
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CodedBitstreamUnit *unit, |
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PutBitContext *pbc) |
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{ |
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int err; |
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switch (unit->type) { |
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#define START(start_code, type, func) \ |
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case start_code: \ |
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err = cbs_mpeg2_write_ ## func(ctx, pbc, unit->content); \ |
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break; |
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START(MPEG2_START_PICTURE, MPEG2RawPictureHeader, picture_header); |
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START(MPEG2_START_USER_DATA, MPEG2RawUserData, user_data); |
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START(MPEG2_START_SEQUENCE_HEADER, MPEG2RawSequenceHeader, sequence_header); |
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START(MPEG2_START_EXTENSION, MPEG2RawExtensionData, extension_data); |
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START(MPEG2_START_GROUP, MPEG2RawGroupOfPicturesHeader, |
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group_of_pictures_header); |
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START(MPEG2_START_SEQUENCE_END, MPEG2RawSequenceEnd, sequence_end); |
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#undef START |
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default: |
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av_log(ctx->log_ctx, AV_LOG_ERROR, "Write unimplemented for start " |
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"code %02"PRIx32".\n", unit->type); |
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return AVERROR_PATCHWELCOME; |
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} |
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return err; |
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} |
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static int cbs_mpeg2_write_slice(CodedBitstreamContext *ctx, |
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CodedBitstreamUnit *unit, |
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PutBitContext *pbc) |
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{ |
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MPEG2RawSlice *slice = unit->content; |
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int err; |
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err = cbs_mpeg2_write_slice_header(ctx, pbc, &slice->header); |
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if (err < 0) |
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return err; |
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if (slice->data) { |
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size_t rest = slice->data_size - (slice->data_bit_start + 7) / 8; |
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uint8_t *pos = slice->data + slice->data_bit_start / 8; |
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av_assert0(slice->data_bit_start >= 0 && |
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slice->data_size > slice->data_bit_start / 8); |
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if (slice->data_size * 8 + 8 > put_bits_left(pbc)) |
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return AVERROR(ENOSPC); |
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// First copy the remaining bits of the first byte |
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if (slice->data_bit_start % 8) |
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put_bits(pbc, 8 - slice->data_bit_start % 8, |
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*pos++ & MAX_UINT_BITS(8 - slice->data_bit_start % 8)); |
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if (put_bits_count(pbc) % 8 == 0) { |
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// If the writer is aligned at this point, |
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// memcpy can be used to improve performance. |
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// This is the normal case. |
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flush_put_bits(pbc); |
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memcpy(put_bits_ptr(pbc), pos, rest); |
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skip_put_bytes(pbc, rest); |
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} else { |
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// If not, we have to copy manually: |
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for (; rest > 3; rest -= 4, pos += 4) |
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put_bits32(pbc, AV_RB32(pos)); |
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for (; rest; rest--, pos++) |
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put_bits(pbc, 8, *pos); |
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// Align with zeros |
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put_bits(pbc, 8 - put_bits_count(pbc) % 8, 0); |
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} |
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} |
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return 0; |
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} |
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static int cbs_mpeg2_write_unit(CodedBitstreamContext *ctx, |
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CodedBitstreamUnit *unit, |
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PutBitContext *pbc) |
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{ |
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if (MPEG2_START_IS_SLICE(unit->type)) |
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return cbs_mpeg2_write_slice (ctx, unit, pbc); |
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else |
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return cbs_mpeg2_write_header(ctx, unit, pbc); |
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} |
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static int cbs_mpeg2_assemble_fragment(CodedBitstreamContext *ctx, |
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CodedBitstreamFragment *frag) |
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{ |
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uint8_t *data; |
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size_t size, dp; |
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int i; |
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size = 0; |
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for (i = 0; i < frag->nb_units; i++) |
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size += 3 + frag->units[i].data_size; |
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frag->data_ref = av_buffer_alloc(size + AV_INPUT_BUFFER_PADDING_SIZE); |
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if (!frag->data_ref) |
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return AVERROR(ENOMEM); |
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data = frag->data_ref->data; |
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dp = 0; |
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for (i = 0; i < frag->nb_units; i++) { |
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CodedBitstreamUnit *unit = &frag->units[i]; |
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data[dp++] = 0; |
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data[dp++] = 0; |
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data[dp++] = 1; |
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memcpy(data + dp, unit->data, unit->data_size); |
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dp += unit->data_size; |
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} |
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av_assert0(dp == size); |
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memset(data + size, 0, AV_INPUT_BUFFER_PADDING_SIZE); |
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frag->data = data; |
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frag->data_size = size; |
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return 0; |
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} |
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const CodedBitstreamType ff_cbs_type_mpeg2 = { |
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.codec_id = AV_CODEC_ID_MPEG2VIDEO, |
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.priv_data_size = sizeof(CodedBitstreamMPEG2Context), |
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.split_fragment = &cbs_mpeg2_split_fragment, |
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.read_unit = &cbs_mpeg2_read_unit, |
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.write_unit = &cbs_mpeg2_write_unit, |
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.assemble_fragment = &cbs_mpeg2_assemble_fragment, |
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};
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