| /* |
| * 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 READ |
| #define READWRITE read |
| #define RWContext GetBitContext |
| |
| #define xui(width, name, var) do { \ |
| uint32_t value = 0; \ |
| CHECK(ff_cbs_read_unsigned(ctx, rw, width, #name, \ |
| &value, 0, (1 << width) - 1)); \ |
| var = value; \ |
| } while (0) |
| |
| #define ui(width, name) \ |
| xui(width, name, current->name) |
| |
| #define marker_bit() do { \ |
| av_unused uint32_t one; \ |
| CHECK(ff_cbs_read_unsigned(ctx, rw, 1, "marker_bit", &one, 1, 1)); \ |
| } while (0) |
| |
| #define nextbits(width, compare, var) \ |
| (get_bits_left(rw) >= width && \ |
| (var = show_bits(rw, width)) == (compare)) |
| |
| #include "cbs_mpeg2_syntax_template.c" |
| |
| #undef READ |
| #undef READWRITE |
| #undef RWContext |
| #undef xui |
| #undef ui |
| #undef marker_bit |
| #undef nextbits |
| |
| |
| #define WRITE |
| #define READWRITE write |
| #define RWContext PutBitContext |
| |
| #define xui(width, name, var) do { \ |
| CHECK(ff_cbs_write_unsigned(ctx, rw, width, #name, \ |
| var, 0, (1 << width) - 1)); \ |
| } while (0) |
| |
| #define ui(width, name) \ |
| xui(width, name, current->name) |
| |
| #define marker_bit() do { \ |
| CHECK(ff_cbs_write_unsigned(ctx, rw, 1, "marker_bit", 1, 1, 1)); \ |
| } while (0) |
| |
| #define nextbits(width, compare, var) (var) |
| |
| #include "cbs_mpeg2_syntax_template.c" |
| |
| #undef READ |
| #undef READWRITE |
| #undef RWContext |
| #undef xui |
| #undef ui |
| #undef marker_bit |
| #undef nextbits |
| |
| |
| static void cbs_mpeg2_free_user_data(void *unit, uint8_t *content) |
| { |
| MPEG2RawUserData *user = (MPEG2RawUserData*)content; |
| av_buffer_unref(&user->user_data_ref); |
| av_freep(&content); |
| } |
| |
| static void cbs_mpeg2_free_slice(void *unit, uint8_t *content) |
| { |
| MPEG2RawSlice *slice = (MPEG2RawSlice*)content; |
| av_buffer_unref(&slice->header.extra_information_ref); |
| av_buffer_unref(&slice->data_ref); |
| av_freep(&content); |
| } |
| |
| static int cbs_mpeg2_split_fragment(CodedBitstreamContext *ctx, |
| CodedBitstreamFragment *frag, |
| int header) |
| { |
| const uint8_t *start, *end; |
| uint8_t *unit_data; |
| uint32_t start_code = -1, next_start_code = -1; |
| size_t unit_size; |
| int err, i, unit_type; |
| |
| start = avpriv_find_start_code(frag->data, frag->data + frag->data_size, |
| &start_code); |
| for (i = 0;; i++) { |
| end = avpriv_find_start_code(start, frag->data + frag->data_size, |
| &next_start_code); |
| |
| unit_type = start_code & 0xff; |
| |
| // The start and end pointers point at to the byte following the |
| // start_code_identifier in the start code that they found. |
| if (end == frag->data + frag->data_size) { |
| // We didn't find a start code, so this is the final unit. |
| unit_size = end - (start - 1); |
| } else { |
| // Unit runs from start to the beginning of the start code |
| // pointed to by end (including any padding zeroes). |
| unit_size = (end - 4) - (start - 1); |
| } |
| |
| unit_data = av_malloc(unit_size + AV_INPUT_BUFFER_PADDING_SIZE); |
| if (!unit_data) |
| return AVERROR(ENOMEM); |
| memcpy(unit_data, start - 1, unit_size); |
| memset(unit_data + unit_size, 0, AV_INPUT_BUFFER_PADDING_SIZE); |
| |
| err = ff_cbs_insert_unit_data(ctx, frag, i, unit_type, |
| unit_data, unit_size, NULL); |
| if (err < 0) { |
| av_freep(&unit_data); |
| return err; |
| } |
| |
| if (end == frag->data + frag->data_size) |
| break; |
| |
| start_code = next_start_code; |
| 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; |
| |
| if (MPEG2_START_IS_SLICE(unit->type)) { |
| MPEG2RawSlice *slice; |
| int pos, len; |
| |
| err = ff_cbs_alloc_unit_content(ctx, unit, sizeof(*slice), |
| &cbs_mpeg2_free_slice); |
| if (err < 0) |
| return err; |
| slice = unit->content; |
| |
| err = cbs_mpeg2_read_slice_header(ctx, &gbc, &slice->header); |
| if (err < 0) |
| return err; |
| |
| pos = get_bits_count(&gbc); |
| len = unit->data_size; |
| |
| slice->data_size = len - pos / 8; |
| slice->data_ref = av_buffer_alloc(slice->data_size + |
| AV_INPUT_BUFFER_PADDING_SIZE); |
| if (!slice->data_ref) |
| return AVERROR(ENOMEM); |
| slice->data = slice->data_ref->data; |
| |
| memcpy(slice->data, |
| unit->data + pos / 8, slice->data_size); |
| memset(slice->data + slice->data_size, 0, |
| AV_INPUT_BUFFER_PADDING_SIZE); |
| slice->data_bit_start = pos % 8; |
| |
| } else { |
| switch (unit->type) { |
| #define START(start_code, type, read_func, free_func) \ |
| case start_code: \ |
| { \ |
| type *header; \ |
| err = ff_cbs_alloc_unit_content(ctx, unit, \ |
| sizeof(*header), free_func); \ |
| if (err < 0) \ |
| return err; \ |
| header = unit->content; \ |
| err = cbs_mpeg2_read_ ## read_func(ctx, &gbc, header); \ |
| if (err < 0) \ |
| return err; \ |
| } \ |
| break; |
| START(0x00, MPEG2RawPictureHeader, picture_header, NULL); |
| START(0xb2, MPEG2RawUserData, user_data, |
| &cbs_mpeg2_free_user_data); |
| START(0xb3, MPEG2RawSequenceHeader, sequence_header, NULL); |
| START(0xb5, MPEG2RawExtensionData, extension_data, NULL); |
| START(0xb8, MPEG2RawGroupOfPicturesHeader, |
| group_of_pictures_header, NULL); |
| #undef START |
| default: |
| av_log(ctx->log_ctx, AV_LOG_ERROR, "Unknown start code %02"PRIx32".\n", |
| unit->type); |
| return AVERROR_INVALIDDATA; |
| } |
| } |
| |
| 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(0x00, MPEG2RawPictureHeader, picture_header); |
| START(0xb2, MPEG2RawUserData, user_data); |
| START(0xb3, MPEG2RawSequenceHeader, sequence_header); |
| START(0xb5, MPEG2RawExtensionData, extension_data); |
| START(0xb8, MPEG2RawGroupOfPicturesHeader, group_of_pictures_header); |
| #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; |
| GetBitContext gbc; |
| size_t bits_left; |
| int err; |
| |
| err = cbs_mpeg2_write_slice_header(ctx, pbc, &slice->header); |
| if (err < 0) |
| return err; |
| |
| if (slice->data) { |
| if (slice->data_size * 8 + 8 > put_bits_left(pbc)) |
| return AVERROR(ENOSPC); |
| |
| init_get_bits(&gbc, slice->data, slice->data_size * 8); |
| skip_bits_long(&gbc, slice->data_bit_start); |
| |
| while (get_bits_left(&gbc) > 15) |
| put_bits(pbc, 16, get_bits(&gbc, 16)); |
| |
| bits_left = get_bits_left(&gbc); |
| put_bits(pbc, bits_left, get_bits(&gbc, bits_left)); |
| |
| // Align with zeroes. |
| while (put_bits_count(pbc) % 8 != 0) |
| put_bits(pbc, 1, 0); |
| } |
| |
| return 0; |
| } |
| |
| static int cbs_mpeg2_write_unit(CodedBitstreamContext *ctx, |
| CodedBitstreamUnit *unit) |
| { |
| CodedBitstreamMPEG2Context *priv = ctx->priv_data; |
| PutBitContext pbc; |
| int err; |
| |
| if (!priv->write_buffer) { |
| // Initial write buffer size is 1MB. |
| priv->write_buffer_size = 1024 * 1024; |
| |
| reallocate_and_try_again: |
| err = av_reallocp(&priv->write_buffer, priv->write_buffer_size); |
| if (err < 0) { |
| av_log(ctx->log_ctx, AV_LOG_ERROR, "Unable to allocate a " |
| "sufficiently large write buffer (last attempt " |
| "%"SIZE_SPECIFIER" bytes).\n", priv->write_buffer_size); |
| return err; |
| } |
| } |
| |
| init_put_bits(&pbc, priv->write_buffer, priv->write_buffer_size); |
| |
| if (unit->type >= 0x01 && unit->type <= 0xaf) |
| err = cbs_mpeg2_write_slice(ctx, unit, &pbc); |
| else |
| err = cbs_mpeg2_write_header(ctx, unit, &pbc); |
| |
| if (err == AVERROR(ENOSPC)) { |
| // Overflow. |
| priv->write_buffer_size *= 2; |
| goto reallocate_and_try_again; |
| } |
| if (err < 0) { |
| // Write failed for some other reason. |
| return err; |
| } |
| |
| if (put_bits_count(&pbc) % 8) |
| unit->data_bit_padding = 8 - put_bits_count(&pbc) % 8; |
| else |
| unit->data_bit_padding = 0; |
| |
| unit->data_size = (put_bits_count(&pbc) + 7) / 8; |
| flush_put_bits(&pbc); |
| |
| err = ff_cbs_alloc_unit_data(ctx, unit, unit->data_size); |
| if (err < 0) |
| return err; |
| |
| memcpy(unit->data, priv->write_buffer, unit->data_size); |
| |
| return 0; |
| } |
| |
| static int cbs_mpeg2_assemble_fragment(CodedBitstreamContext *ctx, |
| CodedBitstreamFragment *frag) |
| { |
| uint8_t *data; |
| size_t size, dp, sp; |
| 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; |
| |
| for (sp = 0; sp < unit->data_size; sp++) |
| data[dp++] = unit->data[sp]; |
| } |
| |
| av_assert0(dp == size); |
| |
| memset(data + size, 0, AV_INPUT_BUFFER_PADDING_SIZE); |
| frag->data = data; |
| frag->data_size = size; |
| |
| return 0; |
| } |
| |
| static void cbs_mpeg2_close(CodedBitstreamContext *ctx) |
| { |
| CodedBitstreamMPEG2Context *priv = ctx->priv_data; |
| |
| av_freep(&priv->write_buffer); |
| } |
| |
| const CodedBitstreamType ff_cbs_type_mpeg2 = { |
| .codec_id = AV_CODEC_ID_MPEG2VIDEO, |
| |
| .priv_data_size = sizeof(CodedBitstreamMPEG2Context), |
| |
| .split_fragment = &cbs_mpeg2_split_fragment, |
| .read_unit = &cbs_mpeg2_read_unit, |
| .write_unit = &cbs_mpeg2_write_unit, |
| .assemble_fragment = &cbs_mpeg2_assemble_fragment, |
| |
| .close = &cbs_mpeg2_close, |
| }; |