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Diffstat (limited to '')
-rw-r--r-- | media/ffvpx/libavcodec/atsc_a53.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/media/ffvpx/libavcodec/atsc_a53.c b/media/ffvpx/libavcodec/atsc_a53.c new file mode 100644 index 0000000000..29ec71bc5f --- /dev/null +++ b/media/ffvpx/libavcodec/atsc_a53.c @@ -0,0 +1,119 @@ +/* + * 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 <stddef.h> +#include <stdint.h> + +#include "atsc_a53.h" +#include "get_bits.h" + +int ff_alloc_a53_sei(const AVFrame *frame, size_t prefix_len, + void **data, size_t *sei_size) +{ + AVFrameSideData *side_data = NULL; + uint8_t *sei_data; + + if (frame) + side_data = av_frame_get_side_data(frame, AV_FRAME_DATA_A53_CC); + + if (!side_data) { + *data = NULL; + return 0; + } + + *sei_size = side_data->size + 11; + *data = av_mallocz(*sei_size + prefix_len); + if (!*data) + return AVERROR(ENOMEM); + sei_data = (uint8_t*)*data + prefix_len; + + // country code + sei_data[0] = 181; + sei_data[1] = 0; + sei_data[2] = 49; + + /** + * 'GA94' is standard in North America for ATSC, but hard coding + * this style may not be the right thing to do -- other formats + * do exist. This information is not available in the side_data + * so we are going with this right now. + */ + AV_WL32(sei_data + 3, MKTAG('G', 'A', '9', '4')); + sei_data[7] = 3; + sei_data[8] = ((side_data->size/3) & 0x1f) | 0x40; + sei_data[9] = 0; + + memcpy(sei_data + 10, side_data->data, side_data->size); + + sei_data[side_data->size+10] = 255; + + return 0; +} + +int ff_parse_a53_cc(AVBufferRef **pbuf, const uint8_t *data, int size) +{ + AVBufferRef *buf = *pbuf; + GetBitContext gb; + size_t new_size, old_size = buf ? buf->size : 0; + int ret, cc_count; + + if (size < 3) + return AVERROR_INVALIDDATA; + + ret = init_get_bits8(&gb, data, size); + if (ret < 0) + return ret; + + if (get_bits(&gb, 8) != 0x3) // user_data_type_code + return 0; + + skip_bits(&gb, 1); // reserved + if (!get_bits(&gb, 1)) // process_cc_data_flag + return 0; + + skip_bits(&gb, 1); // zero bit + cc_count = get_bits(&gb, 5); + if (!cc_count) + return 0; + + skip_bits(&gb, 8); // reserved + + /* 3 bytes per CC plus one byte marker_bits at the end */ + if (cc_count * 3 >= (get_bits_left(&gb) >> 3)) + return AVERROR_INVALIDDATA; + + new_size = (old_size + cc_count * 3); + + if (new_size > INT_MAX) + return AVERROR_INVALIDDATA; + + /* Allow merging of the cc data from two fields. */ + ret = av_buffer_realloc(pbuf, new_size); + if (ret < 0) + return ret; + + buf = *pbuf; + /* Use of av_buffer_realloc assumes buffer is writeable */ + for (int i = 0; i < cc_count; i++) { + buf->data[old_size++] = get_bits(&gb, 8); + buf->data[old_size++] = get_bits(&gb, 8); + buf->data[old_size++] = get_bits(&gb, 8); + } + + return cc_count; +} |