Changes between Initial Version and Version 1 of Encodings/Statistics

Timestamp:

01/12/17 11:41:05 (5 years ago)

Author:

Antoine Martin

Comment:

--

Encodings/Statistics

@@ +1 @@
+= Encoding Statistics =
+
+'''Warning: this page is quite out of date now.'''
+
+{{{#!div class="box"
+As part of encoding improvements (mostly in #419), we have collected encoding performance statistics for 4 still test pictures using the current crop of codec code (pre-release version 0.13).
+
+These encodings are also used when a video encoding is selected as primary encoding, this is done to optimize bandwidth and CPU usage: video encodings require a full frame every time, so we use still picture encodings for smaller regions and for automatic lossless refresh.
+}}}
+
+
+{{{#!div class="box"
+|||||||||| Mode ||||=Desktop 2560x1600=||||=Browser 1920x1080=||||=Diagram 640x800||||=Small Alpha 64x48||
+||Encoding||Compressor||Preset||Quality||Speed||MPixels/s||comp||MPixels/s||comp||MPixels/s||comp||MPixels/s||comp||
+||png||PIL (old)||optimized|| || 0|| 1.6|| 8.1||
+||png||PIL (old)|| || || 100|| 6.5|| 8.5||
+||png||PIL|| || || 100|| 11.6|| 10.0|| 16.1|| 3.1|| 14.6|| 5.0|| 6.0|| 30.1||
+||png/P||PIL|| || || 100|| 21.8|| 4.7|| 17.2|| 9.0|| 23.9|| 3.9|| 2.2|| 14.0||
+||png/L||PIL|| || || 100|| 24.3|| 3.8|| 31.1|| 1.4|| 29.7|| 2.6|| 7.6|| 4.7||
+||webp||PIL|| || 0|| || 5.5|| 0.5|| 6.3|| 0.5|| 5.9|| 0.7|| 0.4|| 13.4||
+||webp||PIL|| || 50|| || 5.1|| 2.1|| 6.0|| 1.1|| 5.6|| 1.6|| 0.4|| 16.7||
+||webp||PIL|| || 100|| || 4.3|| 6.2|| 5.9|| 3.1|| 5.3|| 4.3|| 0.4|| 28.8||
+||jpeg||PIL||optimized|| 0|| || 71.0|| 0.5|| 68.5|| 0.4|| 80.6|| 0.5|| 16.6|| 3.2||
+||jpeg||PIL|| || 50|| || 86.0|| 3.1|| 68.1|| 1.9|| 68.2|| 2.5|| 12.7|| 8.8||
+||jpeg||PIL||optimized|| 100|| || 48.0|| 10.8|| 56.8|| 5.7|| 56.0|| 7.7|| 9.5|| 26.1||
+||jpeg||PIL|| || 100|| || 72.0|| 13.0|| 58.4|| 5.7|| 56.5|| 7.7|| 8.4|| 26.1||
+||rgb||lz4|| || || 100|| 224.0|| 15.0|| 497.0|| 4.3|| 526.0|| 6.9|| 76.7|| 56.0||
+||rgb||zlib|| || || 50|| 21.0|| 9.1|| 30.2|| 2.5|| 27.8|| 3.1|| 11.3|| 39.4||
+||webp||python-webm|| || 0|| || 6.0|| 0.8|| 6.7|| 0.5|| 6.2|| 0.7|| 0.5|| 13.4||
+||webp||python-webm|| || 50|| || 5.3|| 2.1|| 6.5|| 1.1|| 5.7|| 1.6|| 0.6|| 16.7||
+||webp||python-webm|| || 100|| || 0.3|| 4.8|| 1.0|| 0.7|| 0.7|| 1.6|| 0.1|| 25.0||
+||webp||Cython||TEXT|| 0|| 100|| 18.6|| 0.6|| 19.4|| 0.4|| 18.9|| 0.6|| 1.5|| 2.9||
+||webp||Cython||TEXT|| 50|| 100|| 15.5|| 2.7|| 17.7|| 1.5|| 16.6|| 2.2|| 1.2|| 11.9||
+||webp||Cython||TEXT|| 99|| 100|| 12.6|| 6.7|| 15.2|| 3.3|| 13.9|| 4.6|| 0.8|| 29.7||
+||webp||Cython||TEXT + lossless|| 100|| 0|| 0.1|| 4.9|| 0.6|| 0.7|| 0.3|| 1.6|| 0.0|| 24.7||
+||webp||Cython||TEXT + lossless|| 100|| 100|| 2.3|| 5.9|| 27.8|| 1.3|| 27.2|| 1.9|| 1.5|| 26.9||
+}}}
+
+{{{#!div class="box"
+== Notes ==
+* all tests were performed on an AMD FX-8150 (octa-core 3GHz AMD CPU)
+* video encodings are not included, and should generally be preferred to the single picture encodings shown here
+* this shows both speed in mega pixels per second (higher is better), and compression ratio (lower is better)
+* Low quality at low speed doesn't really make much sense, so some values have been omitted
+* changing the {{{webp}}} preset does not affect speed or output size much, it probably does affect the perceived picture quality (seems best to stick with TEXT to ensure that text remains readable)
+* The new {{{webp}}} encoder seems to perform about the same with speeds >50%, only low speed is really slow, and lossless is unbearably slow (it can take more than 30 seconds to encode a single frame using lossless + low speed!)
+* quality is not the same for each encoder, some have lossless modes others not, etc..
+* for data showing the differences between the various {{{png}}} compression types ({{{HUFFMAN_ONLY}}}, {{{FIXED}}}, {{{RLE}}}, {{{FILTERED}}}, {{{DEFAULT}}}), see ticket:419#comment:6
+
+[[BR]]
+You can find a much more detailed analysis (but which is limited to lossy formats in {{{YUV420}}} colourspace mode...) here: [http://people.mozilla.org/~josh/lossy_compressed_image_study_july_2014/ Lossy Compressed Image Formats Study]
+}}}