On Wed, Mar 21, 2018 at 10:19:58PM +0530, Gagandeep Singh wrote: > alpha decompanding curve added to post process the decoded alpha channel > --- > libavcodec/cfhd.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/libavcodec/cfhd.c b/libavcodec/cfhd.c > index fd5555834b..e35732df45 100644 > --- a/libavcodec/cfhd.c > +++ b/libavcodec/cfhd.c > @@ -37,6 +37,9 @@ > #include "thread.h" > #include "cfhd.h" > > +#define ALPHA_COMPAND_DC_OFFSET 256 > +#define ALPHA_COMPAND_GAIN 9400 > + > enum CFHDParam { > ChannelCount = 12, > SubbandCount = 14, > @@ -94,6 +97,20 @@ static inline int dequant_and_decompand(int level, int > quantisation) > FFSIGN(level) * quantisation; > } > > +static inline void process_alpha(int16_t *alpha, int width) > +{ > + int i, channel; > + for (i = 0; i < width; i++) { > + channel = alpha[i]; > + channel -= ALPHA_COMPAND_DC_OFFSET; > + channel <<= 3; > + channel *= ALPHA_COMPAND_GAIN;
Any reason why you can't merge the << 3 (ie. * 8) with the * ALPHA_COMPAND_GAIN ? > + channel >>= 16; > + channel = av_clip_uintp2(channel, 12); > + alpha[i] = channel; Here you should affect the result of av_clip_uintp2 directly to alpha[i]. Actually, I think it would be more readable by dropping the channel intermediate variable entirely. You could write this function like this (untested): static inline void process_alpha(int16_t *alpha, int width) { for (int i = 0; i < width; i++) alpha[i] = av_clip_uintp2(((alpha[i] - 256) * 75200) >> 16, 12); } Of course, you can use DC_OFFSET and GAIN constants in there if you think it is more readable. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel