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Code Issues Releases Activity

atrac3: separate window initialization from IMDCT initialization

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This commit is contained in:
Justin Ruggles
2012-10-18 22:56:10 -04:00
parent c51311b907
commit 78edce3f19
1 changed files with 9 additions and 12 deletions
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21
libavcodec/atrac3.c
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@@ -174,7 +174,7 @@ static int decode_bytes(const uint8_t *input, uint8_t *out, int bytes)
return off; return off;
} }
static av_cold int init_atrac3_transforms(ATRAC3Context *q) static av_cold void init_atrac3_window(void)
{ {
float enc_window[256]; float enc_window[256];
int i; int i;
@@ -184,17 +184,12 @@ static av_cold int init_atrac3_transforms(ATRAC3Context *q)
for (i = 0; i < 256; i++) for (i = 0; i < 256; i++)
enc_window[i] = (sin(((i + 0.5) / 256.0 - 0.5) * M_PI) + 1.0) * 0.5; enc_window[i] = (sin(((i + 0.5) / 256.0 - 0.5) * M_PI) + 1.0) * 0.5;
if (!mdct_window[0]) { for (i = 0; i < 256; i++) {
for (i = 0; i < 256; i++) { mdct_window[i] = enc_window[i] /
mdct_window[i] = enc_window[i] / (enc_window[ i] * enc_window[ i] +
(enc_window[ i] * enc_window[ i] + enc_window[255 - i] * enc_window[255 - i]);
enc_window[255 - i] * enc_window[255 - i]); mdct_window[511 - i] = mdct_window[i];
mdct_window[511 - i] = mdct_window[i];
}
} }
/* initialize the MDCT transform */
return ff_mdct_init(&q->mdct_ctx, 9, 1, 1.0 / 32768);
} }
static av_cold int atrac3_decode_close(AVCodecContext *avctx) static av_cold int atrac3_decode_close(AVCodecContext *avctx)
@@ -956,12 +951,14 @@ static av_cold int atrac3_decode_init(AVCodecContext *avctx)
avctx->sample_fmt = AV_SAMPLE_FMT_FLTP; avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
if ((ret = init_atrac3_transforms(q))) { /* initialize the MDCT transform */
if ((ret = ff_mdct_init(&q->mdct_ctx, 9, 1, 1.0 / 32768)) < 0) {
av_log(avctx, AV_LOG_ERROR, "Error initializing MDCT\n"); av_log(avctx, AV_LOG_ERROR, "Error initializing MDCT\n");
av_freep(&q->decoded_bytes_buffer); av_freep(&q->decoded_bytes_buffer);
return ret; return ret;
} }
init_atrac3_window();
ff_atrac_generate_tables(); ff_atrac_generate_tables();
/* Generate gain tables */ /* Generate gain tables */