dany/libwebp
1
0
Fork 0
mirror of https://github.com/webmproject/libwebp.git synced 2025-02-13 07:22:52 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity

gif2webp: Different kmin/kmax defaults for lossy and lossless

Browse Source 
These were the best values found considering the compression gain and
decoding speed.

Change-Id: Iddae4c5b78c6aa42b1f8a034d1c1b93843071a81
This commit is contained in:
Urvang Joshi 2013-09-30 14:25:58 -07:00
parent 92d47e4ca9
commit fb887f7fe6
2 changed files with 17 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
examples/gif2webp.c
View File

@ -307,8 +307,11 @@ int main(int argc, const char *argv[]) {
WebPData webp_data = { NULL, 0 };
int stored_icc = 0; // Whether we have already stored an ICC profile.
int stored_xmp = 0;
size_t kmin = 9;
size_t kmax = 17;
int default_kmin = 1; // Whether to use default kmin value.
int default_kmax = 1;
size_t kmin = 0;
size_t kmax = 0;
memset(&frame, 0, sizeof(frame));
frame.id = WEBP_CHUNK_ANMF;
@ -341,8 +344,10 @@ int main(int argc, const char *argv[]) {
config.method = strtol(argv[++c], NULL, 0);
} else if (!strcmp(argv[c], "-kmax") && c < argc - 1) {
kmax = strtoul(argv[++c], NULL, 0);
default_kmax = 0;
} else if (!strcmp(argv[c], "-kmin") && c < argc - 1) {
kmin = strtoul(argv[++c], NULL, 0);
default_kmin = 0;
} else if (!strcmp(argv[c], "-f") && c < argc - 1) {
config.filter_strength = strtol(argv[++c], NULL, 0);
} else if (!strcmp(argv[c], "-version")) {
@ -366,6 +371,13 @@ int main(int argc, const char *argv[]) {
}
}
// Appropriate default kmin, kmax values for lossy and lossless.
if (default_kmin) {
kmin = config.lossless ? 9 : 3;
}
if (default_kmax) {
kmax = config.lossless ? 17 : 5;
}
SanitizeKeyFrameIntervals(&kmin, &kmax);
cache = WebPFrameCacheNew(kmin, kmax);

6
man/gif2webp.1
View File

@ -1,5 +1,5 @@
.\" Hey, EMACS: -*- nroff -*-
.TH GIF2WEBP 1 "February 01, 2013"
.TH GIF2WEBP 1 "September 30, 2013"
.SH NAME
gif2webp \- Convert a GIF image to WebP
.SH SYNOPSIS
@ -58,8 +58,8 @@ some key frames into the output animation as needed so that this criteria is
satisfied.
.br
A 'kmin' value of 0 will turn off insertion of key frames.
Typical values are in the range 5 to 30. Default values are kmin = 9 and
kmax = 17.
Typical values are in the range 3 to 30. Default values are kmin = 9,
kmax = 17 for lossless compression and kmin = 3, kmax = 5 for lossy compression.
.br
These two options are relevant only for animated images with large number of
frames (>50).