generic-library/ffmpeg
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

4xm: refactor decode_p_block

Browse Source 
Directly return from code 1, 2 and 6 codepaths and simplify the
remaining one to have a single overflow check and a single call to
mcdc.
This commit is contained in:
Luca Barbato 2013-06-09 21:50:57 +02:00
parent 94aefb1932
commit fbd0dacc8d
1 changed files with 30 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

61
libavcodec/4xm.c
View File

@ -342,52 +342,26 @@ static int decode_p_block(FourXContext *f, uint16_t *dst, uint16_t *src,
uint16_t *start = (uint16_t *)f->last_picture->data[0];
uint16_t *end = start + stride * (f->avctx->height - h + 1) - (1 << log2w);
int ret;
int scale = 1;
unsigned dc = 0;
if (code < 0 || code > 6 || log2w < 0)
return AVERROR_INVALIDDATA;
if (code == 0) {
src += f->mv[bytestream2_get_byte(&f->g)];
if (start > src || src > end) {
av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");
return AVERROR_INVALIDDATA;
}
mcdc(dst, src, log2w, h, stride, 1, 0);
} else if (code == 1) {
if (code == 1) {
log2h--;
if ((ret = decode_p_block(f, dst, src, log2w, log2h, stride)) < 0)
return ret;
if ((ret = decode_p_block(f, dst + (stride << log2h),
return decode_p_block(f, dst + (stride << log2h),
src + (stride << log2h),
log2w, log2h, stride)) < 0)
return ret;
log2w, log2h, stride);
} else if (code == 2) {
log2w--;
if ((ret = decode_p_block(f, dst , src, log2w, log2h, stride)) < 0)
return ret;
if ((ret = decode_p_block(f, dst + (1 << log2w),
return decode_p_block(f, dst + (1 << log2w),
src + (1 << log2w),
log2w, log2h, stride)) < 0)
return ret;
} else if (code == 3 && f->version < 2) {
if (start > src || src > end) {
av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");
return AVERROR_INVALIDDATA;
}
mcdc(dst, src, log2w, h, stride, 1, 0);
} else if (code == 4) {
src += f->mv[bytestream2_get_byte(&f->g)];
if (start > src || src > end) {
av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");
return AVERROR_INVALIDDATA;
}
mcdc(dst, src, log2w, h, stride, 1, bytestream2_get_le16(&f->g2));
} else if (code == 5) {
if (start > src || src > end) {
av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");
return AVERROR_INVALIDDATA;
}
mcdc(dst, src, log2w, h, stride, 0, bytestream2_get_le16(&f->g2));
log2w, log2h, stride);
} else if (code == 6) {
if (log2w) {
dst[0] = bytestream2_get_le16(&f->g2);
@ -396,7 +370,28 @@ static int decode_p_block(FourXContext *f, uint16_t *dst, uint16_t *src,
dst[0] = bytestream2_get_le16(&f->g2);
dst[stride] = bytestream2_get_le16(&f->g2);
}
return 0;
}
if (code == 0) {
src += f->mv[bytestream2_get_byte(&f->g)];
} else if (code == 3 && f->version >= 2) {
return 0;
} else if (code == 4) {
src += f->mv[bytestream2_get_byte(&f->g)];
dc = bytestream2_get_le16(&f->g2);
} else if (code == 5) {
scale = 0;
dc = bytestream2_get_le16(&f->g2);
}
if (start > src || src > end) {
av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");
return AVERROR_INVALIDDATA;
}
mcdc(dst, src, log2w, h, stride, scale, dc);
return 0;
}