adts_header.h (2919B)
1 /* 2 * AAC ADTS header decoding prototypes and structures 3 * Copyright (c) 2003 Fabrice Bellard 4 * Copyright (c) 2003 Michael Niedermayer 5 * 6 * This file is part of FFmpeg. 7 * 8 * FFmpeg is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; either 11 * version 2.1 of the License, or (at your option) any later version. 12 * 13 * FFmpeg is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with FFmpeg; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 */ 22 23 #ifndef AVCODEC_ADTS_HEADER_H 24 #define AVCODEC_ADTS_HEADER_H 25 26 #include "adts_parser.h" 27 #include "defs.h" 28 29 typedef enum { 30 AAC_PARSE_ERROR_SYNC = -0x1030c0a, 31 AAC_PARSE_ERROR_SAMPLE_RATE = -0x3030c0a, 32 AAC_PARSE_ERROR_FRAME_SIZE = -0x4030c0a, 33 } AACParseError; 34 35 typedef struct AACADTSHeaderInfo { 36 uint32_t sample_rate; 37 uint32_t samples; 38 uint32_t bit_rate; 39 uint8_t crc_absent; 40 uint8_t object_type; 41 uint8_t sampling_index; 42 uint8_t chan_config; 43 uint8_t num_aac_frames; 44 uint32_t frame_length; 45 } AACADTSHeaderInfo; 46 47 struct GetBitContext; 48 49 /** 50 * Parse the ADTS frame header to the end of the variable header, which is 51 * the first 54 bits. 52 * @param[in] gbc BitContext containing the first 54 bits of the frame. 53 * @param[out] hdr Pointer to struct where header info is written. 54 * @return the size in bytes of the header parsed on success and 55 * AAC_PARSE_ERROR_* values otherwise. 56 */ 57 int ff_adts_header_parse(struct GetBitContext *gbc, AACADTSHeaderInfo *hdr); 58 59 /** 60 * Wrapper around ff_adts_header_parse() for users that don't already have 61 * a suitable GetBitContext. 62 */ 63 int ff_adts_header_parse_buf(const uint8_t buf[AV_AAC_ADTS_HEADER_SIZE + AV_INPUT_BUFFER_PADDING_SIZE], 64 AACADTSHeaderInfo *hdr); 65 66 /** 67 * Parse the ADTS frame header contained in the buffer, which is 68 * the first 54 bits. 69 * @param[in] buf Pointer to buffer containing the first 54 bits of the frame. 70 * @param[in] size Size of buffer containing the first 54 bits of the frame. 71 * @param[out] phdr Pointer to pointer to struct AACADTSHeaderInfo for which 72 * memory is allocated and header info is written into it. After using the header 73 * information, the allocated memory must be freed by using av_free. 74 * @return 0 on success, AAC_PARSE_ERROR_* values on invalid input and 75 * ordinary AVERROR codes otherwise. 76 */ 77 int avpriv_adts_header_parse(AACADTSHeaderInfo **phdr, const uint8_t *buf, size_t size); 78 79 #endif /* AVCODEC_ADTS_HEADER_H */