/* * 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 "startcode.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; uint32_t start_code = -1; int err; 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; } do { CodedBitstreamUnitType unit_type = start_code & 0xff; const uint8_t *end; size_t unit_size; // Reset start_code to ensure that avpriv_find_start_code() // really reads a new start code and does not reuse the old // start code in any way (as e.g. happens when there is a // Sequence End unit at the very end of a packet). start_code = UINT32_MAX; 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; } err = ff_cbs_append_unit_data(frag, unit_type, (uint8_t*)start, unit_size, frag->data_ref); if (err < 0) return err; start = end; // Do we have a further unit to add to the fragment? } while ((start_code >> 8) == 0x000001); 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_content(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), .type.ref = { .nb_offsets = 2, .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, };