/*
- * ADX ADPCM codecs
- * Copyright (c) 2001,2003 BERO
+ * Copyright (c) 2011 Justin Ruggles
*
- * 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
*/
-#include "avcodec.h"
-#include "adx.h"
-
-/**
- * @file adx.c
- * SEGA CRI adx codecs.
- *
- * Reference documents:
- * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
- * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
- */
-/* 18 bytes <-> 32 samples */
+#include "libavutil/common.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/mathematics.h"
+#include "adx.h"
-static void adx_decode(short *out,const unsigned char *in,PREV *prev)
+void ff_adx_calculate_coeffs(int cutoff, int sample_rate, int bits, int *coeff)
{
- int scale = AV_RB16(in);
- int i;
- int s0,s1,s2,d;
-
-// printf("%x ",scale);
+ double a, b, c;
- in+=2;
- s1 = prev->s1;
- s2 = prev->s2;
- for(i=0;i<16;i++) {
- d = in[i];
- // d>>=4; if (d&8) d-=16;
- d = ((signed char)d >> 4);
- s0 = (BASEVOL*d*scale + SCALE1*s1 - SCALE2*s2)>>14;
- s2 = s1;
- s1 = av_clip_int16(s0);
- *out++=s1;
-
- d = in[i];
- //d&=15; if (d&8) d-=16;
- d = ((signed char)(d<<4) >> 4);
- s0 = (BASEVOL*d*scale + SCALE1*s1 - SCALE2*s2)>>14;
- s2 = s1;
- s1 = av_clip_int16(s0);
- *out++=s1;
- }
- prev->s1 = s1;
- prev->s2 = s2;
+ a = M_SQRT2 - cos(2.0 * M_PI * cutoff / sample_rate);
+ b = M_SQRT2 - 1.0;
+ c = (a - sqrt((a + b) * (a - b))) / b;
+ coeff[0] = lrintf(c * 2.0 * (1 << bits));
+ coeff[1] = lrintf(-(c * c) * (1 << bits));
}
-static void adx_decode_stereo(short *out,const unsigned char *in,PREV *prev)
+int avpriv_adx_decode_header(AVCodecContext *avctx, const uint8_t *buf,
+ int bufsize, int *header_size, int *coeff)
{
- short tmp[32*2];
- int i;
+ int offset, cutoff;
- adx_decode(tmp ,in ,prev);
- adx_decode(tmp+32,in+18,prev+1);
- for(i=0;i<32;i++) {
- out[i*2] = tmp[i];
- out[i*2+1] = tmp[i+32];
- }
-}
+ if (bufsize < 24)
+ return AVERROR_INVALIDDATA;
-/* return data offset or 0 */
-static int adx_decode_header(AVCodecContext *avctx,const unsigned char *buf,size_t bufsize)
-{
- int offset;
+ if (AV_RB16(buf) != 0x8000)
+ return AVERROR_INVALIDDATA;
+ offset = AV_RB16(buf + 2) + 4;
- if (buf[0]!=0x80) return 0;
- offset = (AV_RB32(buf)^0x80000000)+4;
- if (bufsize<offset || memcmp(buf+offset-6,"(c)CRI",6)) return 0;
+ /* if copyright string is within the provided data, validate it */
+ if (bufsize >= offset && offset >= 6 && memcmp(buf + offset - 6, "(c)CRI", 6))
+ return AVERROR_INVALIDDATA;
- avctx->channels = buf[7];
- avctx->sample_rate = AV_RB32(buf+8);
- avctx->bit_rate = avctx->sample_rate*avctx->channels*18*8/32;
+ /* check for encoding=3 block_size=18, sample_size=4 */
+ if (buf[4] != 3 || buf[5] != 18 || buf[6] != 4) {
+ avpriv_request_sample(avctx, "Support for this ADX format");
+ return AVERROR_PATCHWELCOME;
+ }
- return offset;
-}
+ /* channels */
+ avctx->channels = buf[7];
+ if (avctx->channels <= 0 || avctx->channels > 2)
+ return AVERROR_INVALIDDATA;
-static int adx_decode_frame(AVCodecContext *avctx,
- void *data, int *data_size,
- uint8_t *buf0, int buf_size)
-{
- ADXContext *c = avctx->priv_data;
- short *samples = data;
- const uint8_t *buf = buf0;
- int rest = buf_size;
-
- if (!c->header_parsed) {
- int hdrsize = adx_decode_header(avctx,buf,rest);
- if (hdrsize==0) return -1;
- c->header_parsed = 1;
- buf += hdrsize;
- rest -= hdrsize;
- }
+ /* sample rate */
+ avctx->sample_rate = AV_RB32(buf + 8);
+ if (avctx->sample_rate < 1 ||
+ avctx->sample_rate > INT_MAX / (avctx->channels * BLOCK_SIZE * 8))
+ return AVERROR_INVALIDDATA;
- /* 18 bytes of data are expanded into 32*2 bytes of audio,
- so guard against buffer overflows */
- if(rest/18 > *data_size/64)
- rest = (*data_size/64) * 18;
+ /* bit rate */
+ avctx->bit_rate = avctx->sample_rate * avctx->channels * BLOCK_SIZE * 8 / BLOCK_SAMPLES;
- if (c->in_temp) {
- int copysize = 18*avctx->channels - c->in_temp;
- memcpy(c->dec_temp+c->in_temp,buf,copysize);
- rest -= copysize;
- buf += copysize;
- if (avctx->channels==1) {
- adx_decode(samples,c->dec_temp,c->prev);
- samples += 32;
- } else {
- adx_decode_stereo(samples,c->dec_temp,c->prev);
- samples += 32*2;
- }
+ /* LPC coefficients */
+ if (coeff) {
+ cutoff = AV_RB16(buf + 16);
+ ff_adx_calculate_coeffs(cutoff, avctx->sample_rate, COEFF_BITS, coeff);
}
- //
- if (avctx->channels==1) {
- while(rest>=18) {
- adx_decode(samples,buf,c->prev);
- rest-=18;
- buf+=18;
- samples+=32;
- }
- } else {
- while(rest>=18*2) {
- adx_decode_stereo(samples,buf,c->prev);
- rest-=18*2;
- buf+=18*2;
- samples+=32*2;
- }
- }
- //
- c->in_temp = rest;
- if (rest) {
- memcpy(c->dec_temp,buf,rest);
- buf+=rest;
- }
- *data_size = (uint8_t*)samples - (uint8_t*)data;
-// printf("%d:%d ",buf-buf0,*data_size); fflush(stdout);
- return buf-buf0;
-}
-
-AVCodec adpcm_adx_decoder = {
- "adpcm_adx",
- CODEC_TYPE_AUDIO,
- CODEC_ID_ADPCM_ADX,
- sizeof(ADXContext),
- NULL,
- NULL,
- NULL,
- adx_decode_frame,
-};
+ *header_size = offset;
+ return 0;
+}
projects / ffmpeg / blobdiff