* ADX ADPCM codecs
* Copyright (c) 2001,2003 BERO
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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,
+ * Libav 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
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
- * @file adx.h
+ * @file
* SEGA CRI adx codecs.
*
* Reference documents:
* adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
*/
-#ifndef FFMPEG_ADX_H
-#define FFMPEG_ADX_H
+#ifndef AVCODEC_ADX_H
+#define AVCODEC_ADX_H
-typedef struct {
+#include <stdint.h>
+
+#include "avcodec.h"
+
+typedef struct ADXChannelState {
int s1,s2;
-} PREV;
+} ADXChannelState;
-typedef struct {
- PREV prev[2];
+typedef struct ADXContext {
+ int channels;
+ ADXChannelState prev[2];
int header_parsed;
- unsigned char dec_temp[18*2];
- int in_temp;
+ int eof;
+ int cutoff;
+ int coeff[2];
} ADXContext;
-#define BASEVOL 0x4000
-#define SCALE1 0x7298
-#define SCALE2 0x3350
+#define COEFF_BITS 12
+
+#define BLOCK_SIZE 18
+#define BLOCK_SAMPLES 32
+
+/**
+ * Calculate LPC coefficients based on cutoff frequency and sample rate.
+ *
+ * @param cutoff cutoff frequency
+ * @param sample_rate sample rate
+ * @param bits number of bits used to quantize coefficients
+ * @param[out] coeff 2 quantized LPC coefficients
+ */
+void ff_adx_calculate_coeffs(int cutoff, int sample_rate, int bits, int *coeff);
+
+/**
+ * Decode ADX stream header.
+ * Sets avctx->channels and avctx->sample_rate.
+ *
+ * @param avctx codec context
+ * @param buf header data
+ * @param bufsize data size, should be at least 24 bytes
+ * @param[out] header_size size of ADX header
+ * @param[out] coeff 2 LPC coefficients, can be NULL
+ * @return data offset or negative error code if header is invalid
+ */
+int avpriv_adx_decode_header(AVCodecContext *avctx, const uint8_t *buf,
+ int bufsize, int *header_size, int *coeff);
-#endif /* FFMPEG_ADX_H */
+#endif /* AVCODEC_ADX_H */