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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
commit | 43a97878ce14b72f0981164f87f2e35e14151312 (patch) | |
tree | 620249daf56c0258faa40cbdcf9cfba06de2a846 /media/ffvpx/libavcodec/mpegaudiodecheader.h | |
parent | Initial commit. (diff) | |
download | firefox-upstream.tar.xz firefox-upstream.zip |
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'media/ffvpx/libavcodec/mpegaudiodecheader.h')
-rw-r--r-- | media/ffvpx/libavcodec/mpegaudiodecheader.h | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/media/ffvpx/libavcodec/mpegaudiodecheader.h b/media/ffvpx/libavcodec/mpegaudiodecheader.h new file mode 100644 index 0000000000..ed5d1f3b33 --- /dev/null +++ b/media/ffvpx/libavcodec/mpegaudiodecheader.h @@ -0,0 +1,81 @@ +/* + * MPEG Audio header decoder + * Copyright (c) 2001, 2002 Fabrice Bellard + * + * 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 + */ + +/** + * @file + * MPEG Audio header decoder. + */ + +#ifndef AVCODEC_MPEGAUDIODECHEADER_H +#define AVCODEC_MPEGAUDIODECHEADER_H + +#include <stdint.h> +#include "codec_id.h" + +#define MP3_MASK 0xFFFE0CCF + +#define MPA_DECODE_HEADER \ + int frame_size; \ + int error_protection; \ + int layer; \ + int sample_rate; \ + int sample_rate_index; /* between 0 and 8 */ \ + int bit_rate; \ + int nb_channels; \ + int mode; \ + int mode_ext; \ + int lsf; + +typedef struct MPADecodeHeader { + MPA_DECODE_HEADER +} MPADecodeHeader; + +/* header decoding. MUST check the header before because no + consistency check is done there. Return 1 if free format found and + that the frame size must be computed externally */ +int avpriv_mpegaudio_decode_header(MPADecodeHeader *s, uint32_t header); + +/* useful helper to get MPEG audio stream info. Return -1 if error in + header, otherwise the coded frame size in bytes */ +int ff_mpa_decode_header(uint32_t head, int *sample_rate, + int *channels, int *frame_size, int *bitrate, enum AVCodecID *codec_id); + +/* fast header check for resync */ +static inline int ff_mpa_check_header(uint32_t header){ + /* header */ + if ((header & 0xffe00000) != 0xffe00000) + return -1; + /* version check */ + if ((header & (3<<19)) == 1<<19) + return -1; + /* layer check */ + if ((header & (3<<17)) == 0) + return -1; + /* bit rate */ + if ((header & (0xf<<12)) == 0xf<<12) + return -1; + /* frequency */ + if ((header & (3<<10)) == 3<<10) + return -1; + return 0; +} + +#endif /* AVCODEC_MPEGAUDIODECHEADER_H */ |