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Add gamma encodign/decoding before/after scaling in libswscale

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Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Pedro Arthur
2015-04-17 17:08:42 -03:00
committed by Michael Niedermayer
parent d9555adf06
commit 2a7128f4ed
5 changed files with 139 additions and 1 deletions
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76
libswscale/utils.c
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@@ -960,6 +960,20 @@ SwsContext *sws_alloc_context(void)
return c;
}
static uint16_t * alloc_gamma_tbl(double e)
{
int i = 0;
uint16_t * tbl;
tbl = (uint16_t*)av_malloc(sizeof(uint16_t) * 1 << 16);
if (!tbl)
return NULL;
for (i = 0; i < 65536; ++i) {
tbl[i] = pow(i / 65535.0, e) * 65535.0;
}
return tbl;
}
av_cold int sws_init_context(SwsContext *c, SwsFilter *srcFilter,
SwsFilter *dstFilter)
{
@@ -978,6 +992,7 @@ av_cold int sws_init_context(SwsContext *c, SwsFilter *srcFilter,
const AVPixFmtDescriptor *desc_src;
const AVPixFmtDescriptor *desc_dst;
int ret = 0;
enum AVPixelFormat tmpFmt;
cpu_flags = av_get_cpu_flags();
flags = c->flags;
@@ -1235,6 +1250,61 @@ av_cold int sws_init_context(SwsContext *c, SwsFilter *srcFilter,
}
}
// hardcoded for now
c->gamma_value = 2.2;
tmpFmt = AV_PIX_FMT_RGBA64LE;
if (!unscaled && c->gamma_flag && (srcFormat != tmpFmt || dstFormat != tmpFmt)) {
c->cascaded_context[0] = NULL;
ret = av_image_alloc(c->cascaded_tmp, c->cascaded_tmpStride,
srcW, srcH, tmpFmt, 64);
if (ret < 0)
return ret;
c->cascaded_context[0] = sws_getContext(srcW, srcH, srcFormat,
srcW, srcH, tmpFmt,
flags, NULL, NULL, c->param);
if (!c->cascaded_context[0]) {
return -1;
}
c->cascaded_context[1] = sws_getContext(srcW, srcH, tmpFmt,
dstW, dstH, tmpFmt,
flags | SWS_GAMMA_CORRECT, srcFilter, dstFilter, c->param);
if (!c->cascaded_context[1])
return -1;
c->cascaded_context[2] = NULL;
if (dstFormat != tmpFmt) {
ret = av_image_alloc(c->cascaded1_tmp, c->cascaded1_tmpStride,
dstW, dstH, tmpFmt, 64);
if (ret < 0)
return ret;
c->cascaded_context[2] = sws_getContext(dstW, dstH, tmpFmt,
dstW, dstH, dstFormat,
flags, NULL, NULL, c->param);
if (!c->cascaded_context[2])
return -1;
}
return 0;
}
c->gamma = NULL;
c->inv_gamma = NULL;
if (c->flags & SWS_GAMMA_CORRECT) {
c->gamma = alloc_gamma_tbl(c->gamma_value);
if (!c->gamma)
return AVERROR(ENOMEM);
c->inv_gamma = alloc_gamma_tbl(1.f/c->gamma_value);
if (!c->inv_gamma) {
return AVERROR(ENOMEM);
}
}
if (isBayer(srcFormat)) {
if (!unscaled ||
(dstFormat != AV_PIX_FMT_RGB24 && dstFormat != AV_PIX_FMT_YUV420P)) {
@@ -1977,8 +2047,14 @@ void sws_freeContext(SwsContext *c)
sws_freeContext(c->cascaded_context[0]);
sws_freeContext(c->cascaded_context[1]);
sws_freeContext(c->cascaded_context[2]);
memset(c->cascaded_context, 0, sizeof(c->cascaded_context));
av_freep(&c->cascaded_tmp[0]);
av_freep(&c->cascaded1_tmp[0]);
av_freep(&c->gamma);
av_freep(&c->inv_gamma);
av_free(c);
}