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adx: define and use 2 new macro constants BLOCK_SIZE and BLOCK_SAMPLES

This commit is contained in:
Justin Ruggles 2011-11-20 17:50:46 -05:00
parent d1745619db
commit 05c1f11b56
1 changed files with 17 additions and 14 deletions
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31
libavcodec/adxdec.c
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@ -33,6 +33,9 @@
* adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
*/
#define BLOCK_SIZE 18
#define BLOCK_SAMPLES 32
static av_cold int adx_decode_init(AVCodecContext *avctx)
{
avctx->sample_fmt = AV_SAMPLE_FMT_S16;
@ -54,10 +57,10 @@ static void adx_decode(ADXContext *c, int16_t *out, const uint8_t *in, int ch)
int i;
int s0, s1, s2, d;
init_get_bits(&gb, in + 2, (18 - 2) * 8);
init_get_bits(&gb, in + 2, (BLOCK_SIZE - 2) * 8);
s1 = prev->s1;
s2 = prev->s2;
for (i = 0; i < 32; i++) {
for (i = 0; i < BLOCK_SAMPLES; i++) {
d = get_sbits(&gb, 4);
s0 = ((d << COEFF_BITS) * scale + c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS;
s2 = s1;
@ -100,9 +103,9 @@ static int adx_decode_header(AVCodecContext *avctx, const uint8_t *buf,
return AVERROR_INVALIDDATA;
avctx->sample_rate = AV_RB32(buf + 8);
if (avctx->sample_rate < 1 ||
avctx->sample_rate > INT_MAX / (avctx->channels * 18 * 8))
avctx->sample_rate > INT_MAX / (avctx->channels * BLOCK_SIZE * 8))
return AVERROR_INVALIDDATA;
avctx->bit_rate = avctx->sample_rate * avctx->channels * 18 * 8 / 32;
avctx->bit_rate = avctx->sample_rate * avctx->channels * BLOCK_SIZE * 8 / BLOCK_SAMPLES;
cutoff = AV_RB16(buf + 16);
ff_adx_calculate_coeffs(cutoff, avctx->sample_rate, COEFF_BITS, c->coeff);
@ -133,27 +136,27 @@ static int adx_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
/* 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;
if (rest / (BLOCK_SIZE * c->channels) > *data_size / (BLOCK_SAMPLES * c->channels))
rest = (*data_size / (BLOCK_SAMPLES * c->channels)) * BLOCK_SIZE;
if (c->in_temp) {
int copysize = 18 * avctx->channels - c->in_temp;
int copysize = BLOCK_SIZE * avctx->channels - c->in_temp;
memcpy(c->dec_temp + c->in_temp, buf, copysize);
rest -= copysize;
buf += copysize;
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;
adx_decode(c, samples + 1, c->dec_temp + BLOCK_SIZE, 1);
samples += BLOCK_SAMPLES * c->channels;
}
while (rest >= 18 * c->channels) {
while (rest >= BLOCK_SIZE * 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;
adx_decode(c, samples + 1, buf + BLOCK_SIZE, 1);
rest -= BLOCK_SIZE * c->channels;
buf += BLOCK_SIZE * c->channels;
samples += BLOCK_SAMPLES * c->channels;
}
c->in_temp = rest;