This is required for WebP lossy+Alpha images, where Alpha channel is taking
60-70% of the compression (CPU) cycles.
Also evaluated on 1000 PNG corpus and overall compression speed
is 15-40% better for lossy (PNG+Alpha) compression.
The pure lossless compression numbers are almost same (or little
better) with this change.
Change-Id: I9e5ae7372ed6227a9a5b64cd9cff84c747195a57
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
When a ANMF/FRGM chunk size (read from file) is smaller than ANMF/FRGM header
size (which is constant and implicit), the parser should report an error.
Change-Id: I91d71889937f5133a97f1e83d5254cb2d7f37028
broken since:
ad25032 Merge "multi-threaded alpha encoding for lossy"
this produced an error due to an empty VP8TBuffer struct.
Change-Id: I640809d07d20092c1d660e2b59b58a62a12e4371
Also tweak the code for single image and fragmented image cases, so that
dmux->num_frames_ is always correct.
Change-Id: I31e6904222e4d96a54a0d8c8aa73d43b7a9094e7
new option: 'cwebp -mt ...'
new config flag: config.thread_level
(allowed thread_level are 0 or 1 for now. Maybe more later...)
If -mt is activated (and WEBP_USE_THREAD is used for compile), the alpha-compression
will be done in parallel to RGB coding for lossy. Can save quite a bit of latency...
Has no effect for lossless encoding.
Change-Id: I769d0bf90e7380cf99344ad62cd77277f4df5a46
It now returns ALPHA_FLAG for lossless images with alpha, that don't
have a VP8X chunk.
This is consistent with similar methods WebPMuxGetFeatures() and
WebPGetFeatures().
Change-Id: Ia3a4ca8f3e0f102f478bd33e0727ca5be98593df
larger values are still dealt with in the .cc
~5% faster encoding
Output size is slightly different (variably), because of
different floating-point calculation ordering.
Change-Id: I6ede18b09c753997cf78aa1199a807d9ddb5d4b4
-> split libraries further into decoder / encoder
-> add libwebpdecoder.a in Makefile.unix
-> make dwebp link against libwebpdecoder.a in Makefile.unix
also: in makefile.unix, pass EXTRA_FLAGS to LDFLAGS too
(otherwise, -m32 wouldn't work, e.g.)
Change-Id: Ief3da02a729dd86bbaf949ed048836716941657f
Also use a naming 'extended format' rather than 'container file' to be
consistent with the container specification.
Change-Id: I3b07f95e0244d3534fe17b03f60db22f61e17836
signed integer overflow behavior is undefined, split PrefixEncode() to
two branches to avoid this.
Change-Id: I6e2761d0d77f0aaceafdc4e07232e089c22beb64
* add SSE2 variant for lossless
* speed-up TransformColor calls using specialized TransformColorBlue/Red
* Fuse the Shannon Entropy calls to compute it for X and X+Y simultaneously.
This latter changes the output size a little bit.
Change-Id: Ie5df94da78bf51a58da859c9099b56340da9ec89
