* 2nd-order LPC filter applied to it to form the output signal for a single
* channel.
*/
-static void adx_decode(int16_t *out, const uint8_t *in, ADXChannelState *prev)
+static void adx_decode(ADXContext *c, int16_t *out, const uint8_t *in, int ch)
{
+ ADXChannelState *prev = &c->prev[ch];
int scale = AV_RB16(in);
int i;
int s0, s1, s2, d;
s0 = (BASEVOL * d * scale + SCALE1 * s1 - SCALE2 * s2) >> 14;
s2 = s1;
s1 = av_clip_int16(s0);
- *out++ = s1;
+ *out = s1;
+ out += c->channels;
d = in[i];
d = (signed char)(d << 4) >> 4;
s0 = (BASEVOL * d * scale + SCALE1 * s1 - SCALE2 * s2) >> 14;
s2 = s1;
s1 = av_clip_int16(s0);
- *out++ = s1;
+ *out = s1;
+ out += c->channels;
}
prev->s1 = s1;
prev->s2 = s2;
}
-static void adx_decode_stereo(int16_t *out,const uint8_t *in,
- ADXChannelState *prev)
-{
- short tmp[32*2];
- int i;
-
- 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];
- }
-}
-
/**
* Decode stream header.
*
static int adx_decode_header(AVCodecContext *avctx, const uint8_t *buf,
int bufsize)
{
+ ADXContext *c = avctx->priv_data;
int offset;
if (buf[0] != 0x80)
if (bufsize < offset || memcmp(buf + offset - 6, "(c)CRI", 6))
return AVERROR_INVALIDDATA;
- avctx->channels = buf[7];
+ c->channels = avctx->channels = buf[7];
if (avctx->channels > 2)
return AVERROR_INVALIDDATA;
avctx->sample_rate = AV_RB32(buf + 8);
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;
- }
+ adx_decode(c, samples, c->dec_temp, 0);
+ if (avctx->channels == 2)
+ adx_decode(c, samples + 1, c->dec_temp + 18, 1);
+ samples += 32 * c->channels;
}
- 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;
- }
+ while (rest >= 18 * c->channels) {
+ adx_decode(c, samples, buf, 0);
+ if (c->channels == 2)
+ adx_decode(c, samples + 1, buf + 18, 1);
+ rest -= 18 * c->channels;
+ buf += 18 * c->channels;
+ samples += 32 * c->channels;
}
c->in_temp = rest;