| 28 | #include "libavutil/avassert.h" |
| 29 | |
| 30 | int ff_adts_header_parse(GetBitContext *gbc, AACADTSHeaderInfo *hdr) |
| 31 | { |
| 32 | int size, rdb, ch, sr; |
| 33 | int aot, crc_abs; |
| 34 | |
| 35 | memset(hdr, 0, sizeof(*hdr)); |
| 36 | |
| 37 | if (get_bits(gbc, 12) != 0xfff) |
| 38 | return AAC_PARSE_ERROR_SYNC; |
| 39 | |
| 40 | skip_bits1(gbc); /* id */ |
| 41 | skip_bits(gbc, 2); /* layer */ |
| 42 | crc_abs = get_bits1(gbc); /* protection_absent */ |
| 43 | aot = get_bits(gbc, 2); /* profile_objecttype */ |
| 44 | sr = get_bits(gbc, 4); /* sample_frequency_index */ |
| 45 | if (!ff_mpeg4audio_sample_rates[sr]) |
| 46 | return AAC_PARSE_ERROR_SAMPLE_RATE; |
| 47 | skip_bits1(gbc); /* private_bit */ |
| 48 | ch = get_bits(gbc, 3); /* channel_configuration */ |
| 49 | |
| 50 | skip_bits1(gbc); /* original/copy */ |
| 51 | skip_bits1(gbc); /* home */ |
| 52 | |
| 53 | /* adts_variable_header */ |
| 54 | skip_bits1(gbc); /* copyright_identification_bit */ |
| 55 | skip_bits1(gbc); /* copyright_identification_start */ |
| 56 | size = get_bits(gbc, 13); /* aac_frame_length */ |
| 57 | if (size < AV_AAC_ADTS_HEADER_SIZE) |
| 58 | return AAC_PARSE_ERROR_FRAME_SIZE; |
| 59 | |
| 60 | skip_bits(gbc, 11); /* adts_buffer_fullness */ |
| 61 | rdb = get_bits(gbc, 2); /* number_of_raw_data_blocks_in_frame */ |
| 62 | |
| 63 | hdr->object_type = aot + 1; |
| 64 | hdr->chan_config = ch; |
| 65 | hdr->crc_absent = crc_abs; |
| 66 | hdr->num_aac_frames = rdb + 1; |
| 67 | hdr->sampling_index = sr; |
| 68 | hdr->sample_rate = ff_mpeg4audio_sample_rates[sr]; |
| 69 | hdr->samples = (rdb + 1) * 1024; |
| 70 | hdr->bit_rate = size * 8 * hdr->sample_rate / hdr->samples; |
| 71 | hdr->frame_length = size; |
| 72 | |
| 73 | return size; |
| 74 | } |
| 75 | |
| 76 | int ff_adts_header_parse_buf(const uint8_t buf[AV_AAC_ADTS_HEADER_SIZE + AV_INPUT_BUFFER_PADDING_SIZE], |
| 77 | AACADTSHeaderInfo *hdr) |
no test coverage detected