1.5x-2x faster encoding for method 3 and up

using token-buffer (that is: slightly more memory. O(output_size))

This change is ON by default. To return to previous behaviour, use
'cwebp -low_memory' or set config.low_memory to true.

Side-effect of this new mode: it forces 1 partition only (which was
default anyway), and makes some statistics about the bitstream
no longer available. cwebp will no longer report 'intra4-coeffs', etc.

This mode also doesn't work (yet) with multi-pass, and -low_memory
is currently forced for multi-pass.

also: reversed the flag: USE_TOKEN_BUFFER -> DISABLE_TOKEN_BUFFER
also: fixed the kAverageBytesPerMB estimate

Change-Id: I4ea80382038d6df4309663e0cb7bd88d9bca9cf1
This commit is contained in:
skal
2013-03-12 00:37:42 +01:00
committed by James Zern
parent be2fd1735a
commit 9bfbdd144f
10 changed files with 346 additions and 184 deletions

View File

@@ -48,6 +48,7 @@ int WebPConfigInitInternal(WebPConfig* config,
config->image_hint = WEBP_HINT_DEFAULT;
config->emulate_jpeg_size = 0;
config->thread_level = 0;
config->low_memory = 0;
// TODO(skal): tune.
switch (preset) {
@@ -128,6 +129,8 @@ int WebPValidateConfig(const WebPConfig* config) {
return 0;
if (config->thread_level < 0 || config->thread_level > 1)
return 0;
if (config->low_memory < 0 || config->low_memory > 1)
return 0;
return 1;
}