From 3cac899af968f9963241c0d0236a16d70eb6b06d Mon Sep 17 00:00:00 2001 From: Alex Converse Date: Mon, 12 Jul 2010 18:52:03 +0000 Subject: Split the ADTS header decoder off of the ADTS parser. The AAC decoder and ADTS-to-ASC BSF both require the header decoder but not full parsing capabilities. Originally committed as revision 24217 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/aacadtsdec.h | 54 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 libavcodec/aacadtsdec.h (limited to 'libavcodec/aacadtsdec.h') diff --git a/libavcodec/aacadtsdec.h b/libavcodec/aacadtsdec.h new file mode 100644 index 0000000000..bdc577179f --- /dev/null +++ b/libavcodec/aacadtsdec.h @@ -0,0 +1,54 @@ +/* + * AAC ADTS header decoding prototypes and structures + * Copyright (c) 2003 Fabrice Bellard + * Copyright (c) 2003 Michael Niedermayer + * + * 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 + */ + +#ifndef AVCODEC_AACADTSDEC_H +#define AVCODEC_AACADTSDEC_H + +#include +#include "get_bits.h" + +#define AAC_ADTS_HEADER_SIZE 7 + +typedef struct { + uint32_t sample_rate; + uint32_t samples; + uint32_t bit_rate; + uint8_t crc_absent; + uint8_t object_type; + uint8_t sampling_index; + uint8_t chan_config; + uint8_t num_aac_frames; +} AACADTSHeaderInfo; + +/** + * Parse AAC frame header. + * Parse the ADTS frame header to the end of the variable header, which is + * the first 54 bits. + * @param gbc BitContext containing the first 54 bits of the frame. + * @param hdr Pointer to struct where header info is written. + * @return Returns 0 on success, -1 if there is a sync word mismatch, + * -2 if the version element is invalid, -3 if the sample rate + * element is invalid, or -4 if the bit rate element is invalid. + */ +int ff_aac_parse_header(GetBitContext *gbc, AACADTSHeaderInfo *hdr); + +#endif /* AVCODEC_AACADTSDEC_H */ -- cgit v1.2.3