[FFmpeg-cvslog] r20281 - trunk/libavcodec/roqaudioenc.c
vitor
subversion
Sun Oct 18 18:29:11 CEST 2009
Author: vitor
Date: Sun Oct 18 18:29:10 2009
New Revision: 20281
Log:
Replace big square-root table by a call to ff_sqrt(). Based on a patch
by Reimar D?ffinger.
Modified:
trunk/libavcodec/roqaudioenc.c
Modified: trunk/libavcodec/roqaudioenc.c
==============================================================================
--- trunk/libavcodec/roqaudioenc.c Sun Oct 18 18:13:29 2009 (r20280)
+++ trunk/libavcodec/roqaudioenc.c Sun Oct 18 18:29:10 2009 (r20281)
@@ -29,7 +29,6 @@
#define MAX_DPCM (127*127)
-static unsigned char dpcmValues[MAX_DPCM];
typedef struct
@@ -37,18 +36,6 @@ typedef struct
short lastSample[2];
} ROQDPCMContext;
-static av_cold void roq_dpcm_table_init(void)
-{
- int i;
-
- /* Create a table of quick DPCM values */
- for (i=0; i<MAX_DPCM; i++) {
- int s= ff_sqrt(i);
- int mid= s*s + s;
- dpcmValues[i]= s + (i>mid);
- }
-}
-
static av_cold int roq_dpcm_encode_init(AVCodecContext *avctx)
{
ROQDPCMContext *context = avctx->priv_data;
@@ -66,8 +53,6 @@ static av_cold int roq_dpcm_encode_init(
return -1;
}
- roq_dpcm_table_init();
-
avctx->frame_size = ROQ_FIRST_FRAME_SIZE;
context->lastSample[0] = context->lastSample[1] = 0;
@@ -92,8 +77,10 @@ static unsigned char dpcm_predict(short
if (diff >= MAX_DPCM)
result = 127;
- else
- result = dpcmValues[diff];
+ else {
+ result = ff_sqrt(diff);
+ result += diff > result*result+result;
+ }
/* See if this overflows */
retry:
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