mpegaudio.h

从FFMPEG转换而来的H264解码程序,VC下编译..

/*
 * copyright (c) 2001 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 mpegaudio.h
 * mpeg audio declarations for both encoder and decoder.
 */

#ifndef MPEGAUDIO_H
#define MPEGAUDIO_H

/* max frame size, in samples */
#define MPA_FRAME_SIZE 1152

#define MPA_MAX_CHANNELS 2

#define SBLIMIT 32 /* number of subbands */

/* define USE_HIGHPRECISION to have a bit exact (but slower) mpeg
   audio decoder */

#ifdef USE_HIGHPRECISION
#define FRAC_BITS   23   /* fractional bits for sb_samples and dct */
#define WFRAC_BITS  16   /* fractional bits for window */
#else
#define FRAC_BITS   15   /* fractional bits for sb_samples and dct */
#define WFRAC_BITS  14   /* fractional bits for window */
#endif

#if defined(USE_HIGHPRECISION) && defined(CONFIG_AUDIO_NONSHORT)
typedef int32_t OUT_INT;
#define OUT_MAX INT32_MAX
#define OUT_MIN INT32_MIN
#define OUT_SHIFT (WFRAC_BITS + FRAC_BITS - 31)
#else
typedef int16_t OUT_INT;
#define OUT_MAX INT16_MAX
#define OUT_MIN INT16_MIN
#define OUT_SHIFT (WFRAC_BITS + FRAC_BITS - 15)
#endif

#if FRAC_BITS <= 15
typedef int16_t MPA_INT;
#else
typedef int32_t MPA_INT;
#endif

void ff_mpa_synth_init(MPA_INT *window);
void ff_mpa_synth_filter(MPA_INT *synth_buf_ptr, int *synth_buf_offset,
                         MPA_INT *window, int *dither_state,
                         OUT_INT *samples, int incr,
                         int32_t sb_samples[SBLIMIT]);

#endif /* MPEGAUDIO_H */