| /* |
| * 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 "libavutil/avassert.h" |
| |
| #include "cbs.h" |
| #include "cbs_internal.h" |
| #include "cbs_mpeg2.h" |
| #include "internal.h" |
| |
| |
| #define HEADER(name) do { \ |
| ff_cbs_trace_header(ctx, name); \ |
| } while (0) |
| |
| #define CHECK(call) do { \ |
| err = (call); \ |
| if (err < 0) \ |
| return err; \ |
| } while (0) |
| |
| #define FUNC_NAME(rw, codec, name) cbs_ ## codec ## _ ## rw ## _ ## name |
| #define FUNC_MPEG2(rw, name) FUNC_NAME(rw, mpeg2, name) |
| #define FUNC(name) FUNC_MPEG2(READWRITE, name) |
| |
| #define SUBSCRIPTS(subs, ...) (subs > 0 ? ((int[subs + 1]){ subs, __VA_ARGS__ }) : NULL) |
| |
| #define ui(width, name) \ |
| xui(width, name, current->name, 0, MAX_UINT_BITS(width), 0, ) |
| #define uir(width, name) \ |
| xui(width, name, current->name, 1, MAX_UINT_BITS(width), 0, ) |
| #define uis(width, name, subs, ...) \ |
| xui(width, name, current->name, 0, MAX_UINT_BITS(width), subs, __VA_ARGS__) |
| #define uirs(width, name, subs, ...) \ |
| xui(width, name, current->name, 1, MAX_UINT_BITS(width), subs, __VA_ARGS__) |
| #define xui(width, name, var, range_min, range_max, subs, ...) \ |
| xuia(width, #name, var, range_min, range_max, subs, __VA_ARGS__) |
| #define sis(width, name, subs, ...) \ |
| xsi(width, name, current->name, subs, __VA_ARGS__) |
| |
| #define marker_bit() \ |
| bit("marker_bit", 1) |
| #define bit(string, value) do { \ |
| av_unused uint32_t bit = value; \ |
| xuia(1, string, bit, value, value, 0, ); \ |
| } while (0) |
| |
| |
| #define READ |
| #define READWRITE read |
| #define RWContext GetBitContext |
| |
| #define xuia(width, string, var, range_min, range_max, subs, ...) do { \ |
| uint32_t value; \ |
| CHECK(ff_cbs_read_unsigned(ctx, rw, width, string, \ |
| SUBSCRIPTS(subs, __VA_ARGS__), \ |
| &value, range_min, range_max)); \ |
| var = value; \ |
| } while (0) |
| |
| #define xsi(width, name, var, subs, ...) do { \ |
| int32_t value; \ |
| CHECK(ff_cbs_read_signed(ctx, rw, width, #name, \ |
| SUBSCRIPTS(subs, __VA_ARGS__), &value, \ |
| MIN_INT_BITS(width), \ |
| MAX_INT_BITS(width))); \ |
| var = value; \ |
| } while (0) |
| |
| #define nextbits(width, compare, var) \ |
| (get_bits_left(rw) >= width && \ |
| (var = show_bits(rw, width)) == (compare)) |
| |
| #define infer(name, value) do { \ |
| current->name = value; \ |
| } while (0) |
| |
| #include "cbs_mpeg2_syntax_template.c" |
| |
| #undef READ |
| #undef READWRITE |
| #undef RWContext |
| #undef xuia |
| #undef xsi |
| #undef nextbits |
| #undef infer |
| |
| |
| #define WRITE |
| #define READWRITE write |
| #define RWContext PutBitContext |
| |
| #define xuia(width, string, var, range_min, range_max, subs, ...) do { \ |
| CHECK(ff_cbs_write_unsigned(ctx, rw, width, string, \ |
| SUBSCRIPTS(subs, __VA_ARGS__), \ |
| var, range_min, range_max)); \ |
| } while (0) |
| |
| #define xsi(width, name, var, subs, ...) do { \ |
| CHECK(ff_cbs_write_signed(ctx, rw, width, #name, \ |
| SUBSCRIPTS(subs, __VA_ARGS__), var, \ |
| MIN_INT_BITS(width), \ |
| MAX_INT_BITS(width))); \ |
| } while (0) |
| |
| #define nextbits(width, compare, var) (var) |
| |
| #define infer(name, value) do { \ |
| if (current->name != (value)) { \ |
| av_log(ctx->log_ctx, AV_LOG_WARNING, "Warning: " \ |
| "%s does not match inferred value: " \ |
| "%"PRId64", but should be %"PRId64".\n", \ |
| #name, (int64_t)current->name, (int64_t)(value)); \ |
| } \ |
| } while (0) |
| |
| #include "cbs_mpeg2_syntax_template.c" |
| |
| #undef WRITE |
| #undef READWRITE |
| #undef RWContext |
| #undef xuia |
| #undef xsi |
| #undef nextbits |
| #undef infer |
| |
| |
| static int cbs_mpeg2_split_fragment(CodedBitstreamContext *ctx, |
| CodedBitstreamFragment *frag, |
| int header) |
| { |
| const uint8_t *start, *end; |
| CodedBitstreamUnitType unit_type; |
| uint32_t start_code = -1; |
| size_t unit_size; |
| int err, i, final = 0; |
| |
| start = avpriv_find_start_code(frag->data, frag->data + frag->data_size, |
| &start_code); |
| if (start_code >> 8 != 0x000001) { |
| // No start code found. |
| return AVERROR_INVALIDDATA; |
| } |
| |
| for (i = 0;; i++) { |
| unit_type = start_code & 0xff; |
| |
| if (start == frag->data + frag->data_size) { |
| // The last four bytes form a start code which constitutes |
| // a unit of its own. In this situation avpriv_find_start_code |
| // won't modify start_code at all so modify start_code so that |
| // the next unit will be treated as the last unit. |
| start_code = 0; |
| } |
| |
| end = avpriv_find_start_code(start--, frag->data + frag->data_size, |
| &start_code); |
| |
| // start points to the byte containing the start_code_identifier |
| // (may be the last byte of fragment->data); end points to the byte |
| // following the byte containing the start code identifier (or to |
| // the end of fragment->data). |
| if (start_code >> 8 == 0x000001) { |
| // Unit runs from start to the beginning of the start code |
| // pointed to by end (including any padding zeroes). |
| unit_size = (end - 4) - start; |
| } else { |
| // We didn't find a start code, so this is the final unit. |
| unit_size = end - start; |
| final = 1; |
| } |
| |
| err = ff_cbs_insert_unit_data(frag, i, unit_type, (uint8_t*)start, |
| unit_size, frag->data_ref); |
| if (err < 0) |
| return err; |
| |
| if (final) |
| break; |
| |
| start = end; |
| } |
| |
| return 0; |
| } |
| |
| static int cbs_mpeg2_read_unit(CodedBitstreamContext *ctx, |
| CodedBitstreamUnit *unit) |
| { |
| GetBitContext gbc; |
| int err; |
| |
| err = init_get_bits(&gbc, unit->data, 8 * unit->data_size); |
| if (err < 0) |
| return err; |
| |
| err = ff_cbs_alloc_unit_content2(ctx, unit); |
| if (err < 0) |
| return err; |
| |
| if (MPEG2_START_IS_SLICE(unit->type)) { |
| MPEG2RawSlice *slice = unit->content; |
| int pos, len; |
| |
| err = cbs_mpeg2_read_slice_header(ctx, &gbc, &slice->header); |
| if (err < 0) |
| return err; |
| |
| if (!get_bits_left(&gbc)) |
| return AVERROR_INVALIDDATA; |
| |
| pos = get_bits_count(&gbc); |
| len = unit->data_size; |
| |
| slice->data_size = len - pos / 8; |
| slice->data_ref = av_buffer_ref(unit->data_ref); |
| if (!slice->data_ref) |
| return AVERROR(ENOMEM); |
| slice->data = unit->data + pos / 8; |
| |
| slice->data_bit_start = pos % 8; |
| |
| } else { |
| switch (unit->type) { |
| #define START(start_code, type, read_func, free_func) \ |
| case start_code: \ |
| { \ |
| type *header = unit->content; \ |
| err = cbs_mpeg2_read_ ## read_func(ctx, &gbc, header); \ |
| if (err < 0) \ |
| return err; \ |
| } \ |
| break; |
| START(MPEG2_START_PICTURE, MPEG2RawPictureHeader, |
| picture_header, &cbs_mpeg2_free_picture_header); |
| START(MPEG2_START_USER_DATA, MPEG2RawUserData, |
| user_data, &cbs_mpeg2_free_user_data); |
| START(MPEG2_START_SEQUENCE_HEADER, MPEG2RawSequenceHeader, |
| sequence_header, NULL); |
| START(MPEG2_START_EXTENSION, MPEG2RawExtensionData, |
| extension_data, NULL); |
| START(MPEG2_START_GROUP, MPEG2RawGroupOfPicturesHeader, |
| group_of_pictures_header, NULL); |
| START(MPEG2_START_SEQUENCE_END, MPEG2RawSequenceEnd, |
| sequence_end, NULL); |
| #undef START |
| default: |
| return AVERROR(ENOSYS); |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int cbs_mpeg2_write_header(CodedBitstreamContext *ctx, |
| CodedBitstreamUnit *unit, |
| PutBitContext *pbc) |
| { |
| int err; |
| |
| switch (unit->type) { |
| #define START(start_code, type, func) \ |
| case start_code: \ |
| err = cbs_mpeg2_write_ ## func(ctx, pbc, unit->content); \ |
| break; |
| START(MPEG2_START_PICTURE, MPEG2RawPictureHeader, picture_header); |
| START(MPEG2_START_USER_DATA, MPEG2RawUserData, user_data); |
| START(MPEG2_START_SEQUENCE_HEADER, MPEG2RawSequenceHeader, sequence_header); |
| START(MPEG2_START_EXTENSION, MPEG2RawExtensionData, extension_data); |
| START(MPEG2_START_GROUP, MPEG2RawGroupOfPicturesHeader, |
| group_of_pictures_header); |
| START(MPEG2_START_SEQUENCE_END, MPEG2RawSequenceEnd, sequence_end); |
| #undef START |
| default: |
| av_log(ctx->log_ctx, AV_LOG_ERROR, "Write unimplemented for start " |
| "code %02"PRIx32".\n", unit->type); |
| return AVERROR_PATCHWELCOME; |
| } |
| |
| return err; |
| } |
| |
| static int cbs_mpeg2_write_slice(CodedBitstreamContext *ctx, |
| CodedBitstreamUnit *unit, |
| PutBitContext *pbc) |
| { |
| MPEG2RawSlice *slice = unit->content; |
| int err; |
| |
| err = cbs_mpeg2_write_slice_header(ctx, pbc, &slice->header); |
| if (err < 0) |
| return err; |
| |
| if (slice->data) { |
| size_t rest = slice->data_size - (slice->data_bit_start + 7) / 8; |
| uint8_t *pos = slice->data + slice->data_bit_start / 8; |
| |
| av_assert0(slice->data_bit_start >= 0 && |
| slice->data_size > slice->data_bit_start / 8); |
| |
| if (slice->data_size * 8 + 8 > put_bits_left(pbc)) |
| return AVERROR(ENOSPC); |
| |
| // First copy the remaining bits of the first byte |
| if (slice->data_bit_start % 8) |
| put_bits(pbc, 8 - slice->data_bit_start % 8, |
| *pos++ & MAX_UINT_BITS(8 - slice->data_bit_start % 8)); |
| |
| if (put_bits_count(pbc) % 8 == 0) { |
| // If the writer is aligned at this point, |
| // memcpy can be used to improve performance. |
| // This is the normal case. |
| flush_put_bits(pbc); |
| memcpy(put_bits_ptr(pbc), pos, rest); |
| skip_put_bytes(pbc, rest); |
| } else { |
| // If not, we have to copy manually: |
| for (; rest > 3; rest -= 4, pos += 4) |
| put_bits32(pbc, AV_RB32(pos)); |
| |
| for (; rest; rest--, pos++) |
| put_bits(pbc, 8, *pos); |
| |
| // Align with zeros |
| put_bits(pbc, 8 - put_bits_count(pbc) % 8, 0); |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int cbs_mpeg2_write_unit(CodedBitstreamContext *ctx, |
| CodedBitstreamUnit *unit, |
| PutBitContext *pbc) |
| { |
| if (MPEG2_START_IS_SLICE(unit->type)) |
| return cbs_mpeg2_write_slice (ctx, unit, pbc); |
| else |
| return cbs_mpeg2_write_header(ctx, unit, pbc); |
| } |
| |
| static int cbs_mpeg2_assemble_fragment(CodedBitstreamContext *ctx, |
| CodedBitstreamFragment *frag) |
| { |
| uint8_t *data; |
| size_t size, dp; |
| int i; |
| |
| size = 0; |
| for (i = 0; i < frag->nb_units; i++) |
| size += 3 + frag->units[i].data_size; |
| |
| frag->data_ref = av_buffer_alloc(size + AV_INPUT_BUFFER_PADDING_SIZE); |
| if (!frag->data_ref) |
| return AVERROR(ENOMEM); |
| data = frag->data_ref->data; |
| |
| dp = 0; |
| for (i = 0; i < frag->nb_units; i++) { |
| CodedBitstreamUnit *unit = &frag->units[i]; |
| |
| data[dp++] = 0; |
| data[dp++] = 0; |
| data[dp++] = 1; |
| |
| memcpy(data + dp, unit->data, unit->data_size); |
| dp += unit->data_size; |
| } |
| |
| av_assert0(dp == size); |
| |
| memset(data + size, 0, AV_INPUT_BUFFER_PADDING_SIZE); |
| frag->data = data; |
| frag->data_size = size; |
| |
| return 0; |
| } |
| |
| static const CodedBitstreamUnitTypeDescriptor cbs_mpeg2_unit_types[] = { |
| CBS_UNIT_TYPE_INTERNAL_REF(MPEG2_START_PICTURE, MPEG2RawPictureHeader, |
| extra_information_picture.extra_information), |
| |
| { |
| .nb_unit_types = CBS_UNIT_TYPE_RANGE, |
| .unit_type_range_start = 0x01, |
| .unit_type_range_end = 0xaf, |
| |
| .content_type = CBS_CONTENT_TYPE_INTERNAL_REFS, |
| .content_size = sizeof(MPEG2RawSlice), |
| .nb_ref_offsets = 2, |
| .ref_offsets = { offsetof(MPEG2RawSlice, header.extra_information_slice.extra_information), |
| offsetof(MPEG2RawSlice, data) }, |
| }, |
| |
| CBS_UNIT_TYPE_INTERNAL_REF(MPEG2_START_USER_DATA, MPEG2RawUserData, |
| user_data), |
| |
| CBS_UNIT_TYPE_POD(MPEG2_START_SEQUENCE_HEADER, MPEG2RawSequenceHeader), |
| CBS_UNIT_TYPE_POD(MPEG2_START_EXTENSION, MPEG2RawExtensionData), |
| CBS_UNIT_TYPE_POD(MPEG2_START_SEQUENCE_END, MPEG2RawSequenceEnd), |
| CBS_UNIT_TYPE_POD(MPEG2_START_GROUP, MPEG2RawGroupOfPicturesHeader), |
| |
| CBS_UNIT_TYPE_END_OF_LIST |
| }; |
| |
| const CodedBitstreamType ff_cbs_type_mpeg2 = { |
| .codec_id = AV_CODEC_ID_MPEG2VIDEO, |
| |
| .priv_data_size = sizeof(CodedBitstreamMPEG2Context), |
| |
| .unit_types = cbs_mpeg2_unit_types, |
| |
| .split_fragment = &cbs_mpeg2_split_fragment, |
| .read_unit = &cbs_mpeg2_read_unit, |
| .write_unit = &cbs_mpeg2_write_unit, |
| .assemble_fragment = &cbs_mpeg2_assemble_fragment, |
| }; |