diff options
Diffstat (limited to 'wsutil/mpeg-audio.h')
| -rw-r--r-- | wsutil/mpeg-audio.h | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/wsutil/mpeg-audio.h b/wsutil/mpeg-audio.h new file mode 100644 index 00000000..10ef36a4 --- /dev/null +++ b/wsutil/mpeg-audio.h @@ -0,0 +1,95 @@ +/** @file + * + * MPEG Audio header dissection + * Written by Shaun Jackman <sjackman@gmail.com> + * Copyright 2007 Shaun Jackman + * + * Wiretap Library + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#ifndef MPA_H +#define MPA_H 1 + +#include <stdint.h> +#include "ws_symbol_export.h" + +struct mpa { + unsigned int emphasis :2; + unsigned int original :1; + unsigned int copyright :1; + unsigned int modeext :2; + unsigned int mode :2; + unsigned int priv :1; + unsigned int padding :1; + unsigned int frequency :2; + unsigned int bitrate :4; + unsigned int protection :1; + unsigned int layer :2; + unsigned int version :2; + unsigned int sync :11; +}; + +#define MPA_UNMARSHAL_SYNC(n) ((n) >> 21 & 0x7ff) +#define MPA_UNMARSHAL_VERSION(n) ((n) >> 19 & 0x3) +#define MPA_UNMARSHAL_LAYER(n) ((n) >> 17 & 0x3) +#define MPA_UNMARSHAL_PROTECTION(n) ((n) >> 16 & 0x1) +#define MPA_UNMARSHAL_BITRATE(n) ((n) >> 12 & 0xf) +#define MPA_UNMARSHAL_FREQUENCY(n) ((n) >> 10 & 0x3) +#define MPA_UNMARSHAL_PADDING(n) ((n) >> 9 & 0x1) +#define MPA_UNMARSHAL_PRIVATE(n) ((n) >> 8 & 0x1) +#define MPA_UNMARSHAL_MODE(n) ((n) >> 6 & 0x3) +#define MPA_UNMARSHAL_MODEEXT(n) ((n) >> 4 & 0x3) +#define MPA_UNMARSHAL_COPYRIGHT(n) ((n) >> 3 & 0x1) +#define MPA_UNMARSHAL_ORIGINAL(n) ((n) >> 2 & 0x1) +#define MPA_UNMARSHAL_EMPHASIS(n) ((n) >> 0 & 0x3) + +#define MPA_UNMARSHAL(mpa, n) do { \ + (mpa)->sync = MPA_UNMARSHAL_SYNC(n); \ + (mpa)->version = MPA_UNMARSHAL_VERSION(n); \ + (mpa)->layer = MPA_UNMARSHAL_LAYER(n); \ + (mpa)->protection = MPA_UNMARSHAL_PROTECTION(n); \ + (mpa)->bitrate = MPA_UNMARSHAL_BITRATE(n); \ + (mpa)->frequency = MPA_UNMARSHAL_FREQUENCY(n); \ + (mpa)->padding = MPA_UNMARSHAL_PADDING(n); \ + (mpa)->priv = MPA_UNMARSHAL_PRIVATE(n); \ + (mpa)->mode = MPA_UNMARSHAL_MODE(n); \ + (mpa)->modeext = MPA_UNMARSHAL_MODEEXT(n); \ + (mpa)->copyright = MPA_UNMARSHAL_COPYRIGHT(n); \ + (mpa)->original = MPA_UNMARSHAL_ORIGINAL(n); \ + (mpa)->emphasis = MPA_UNMARSHAL_EMPHASIS(n); \ + } while (0) + +WS_DLL_PUBLIC +int mpa_version(const struct mpa *); +WS_DLL_PUBLIC +int mpa_layer(const struct mpa *); +WS_DLL_PUBLIC +unsigned int mpa_samples(const struct mpa *); +WS_DLL_PUBLIC +unsigned int mpa_bitrate(const struct mpa *); +WS_DLL_PUBLIC +unsigned int mpa_frequency(const struct mpa *); +WS_DLL_PUBLIC +unsigned int mpa_padding(const struct mpa *); +WS_DLL_PUBLIC +uint32_t decode_synchsafe_int(uint32_t); + +#define MPA_DATA_BYTES(mpa) (mpa_bitrate(mpa) * mpa_samples(mpa) \ + / mpa_frequency(mpa) / 8) +#define MPA_BYTES(mpa) (MPA_DATA_BYTES(mpa) + mpa_padding(mpa)) +#define MPA_DURATION_NS(mpa) \ + (1000000000 / mpa_frequency(mpa) * mpa_samples(mpa)) + +enum { MPA_SYNC = 0x7ff }; + +#define MPA_SYNC_VALID(mpa) ((mpa)->sync == MPA_SYNC) +#define MPA_VERSION_VALID(mpa) (mpa_version(mpa) >= 0) +#define MPA_LAYER_VALID(mpa) (mpa_layer(mpa) >= 0) +#define MPA_BITRATE_VALID(mpa) (mpa_bitrate(mpa) > 0) +#define MPA_FREQUENCY_VALID(mpa) (mpa_frequency(mpa) > 0) +#define MPA_VALID(mpa) (MPA_SYNC_VALID(mpa) \ + && MPA_VERSION_VALID(mpa) && MPA_LAYER_VALID(mpa) \ + && MPA_BITRATE_VALID(mpa) && MPA_FREQUENCY_VALID(mpa)) + +#endif |