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The people.xiph.org server died due to hard drive failure. It isn't coming back according to the xiph folks, heard it from #daala irc.
fixed other dead link too.
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mahanstreamer
2021-08-17 14:48:51 -04:00
committed by GitHub
parent cc275791fd
commit 75ca66124c
1 changed files with 4 additions and 4 deletions
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@@ -695,7 +695,7 @@ When we read the H.264 bitstream spec for an SPS NAL we'll find many values for
| pic_width_in_mbs_minus_1 | 0 | ue(v) |
| pic_height_in_map_units_minus_1 | 0 | ue(v) |
> **ue(v)**: unsigned integer [Exp-Golomb-coded](https://pythonhosted.org/bitstring/exp-golomb.html)
> **ue(v)**: unsigned integer [Exp-Golomb-coded](https://ghostarchive.org/archive/JBwdI)
If we do some math with the value of these fields we will end up with the **resolution**. We can represent a `1920 x 1080` using a `pic_width_in_mbs_minus_1` with the value of `119 ( (119 + 1) * macroblock_size = 120 * 16 = 1920) `, again saving space, instead of encode `1920` we did it with `119`.
@@ -709,7 +709,7 @@ We can see its first 6 bytes values: `01100101 10001000 10000100 00000000 001000
Using the spec info we can decode what type of slice (**slice_type**), the frame number (**frame_num**) among others important fields.
In order to get the values of some fields (`ue(v), me(v), se(v) or te(v)`) we need to decode it using a special decoder called [Exponential-Golomb](https://pythonhosted.org/bitstring/exp-golomb.html), this method is **very efficient to encode variable values**, mostly when there are many default values.
In order to get the values of some fields (`ue(v), me(v), se(v) or te(v)`) we need to decode it using a special decoder called [Exponential-Golomb](https://ghostarchive.org/archive/JBwdI), this method is **very efficient to encode variable values**, mostly when there are many default values.
> The values of **slice_type** and **frame_num** of this video are 7 (I slice) and 0 (the first frame).
@@ -891,7 +891,7 @@ Non-ITU Codecs:
* https://aomedia.googlesource.com/
* https://github.com/webmproject/libvpx/tree/master/vp9
* https://people.xiph.org/~xiphmont/demo/daala/demo1.shtml
* https://ghostarchive.org/archive/0W0d8 (was: https://people.xiph.org/~xiphmont/demo/daala/demo1.shtml)
* https://people.xiph.org/~jm/daala/revisiting/
* https://www.youtube.com/watch?v=lzPaldsmJbk
* https://fosdem.org/2017/schedule/event/om_av1/
@@ -925,7 +925,7 @@ Miscellaneous:
* http://vanseodesign.com/web-design/color-luminance/
* http://www.biologymad.com/nervoussystem/eyenotes.htm
* http://www.compression.ru/video/codec_comparison/h264_2012/mpeg4_avc_h264_video_codecs_comparison.pdf
* http://www.csc.villanova.edu/~rschumey/csc4800/dct.html
* https://web.archive.org/web/20100728070421/http://www.csc.villanova.edu/~rschumey/csc4800/dct.html (was: http://www.csc.villanova.edu/~rschumey/csc4800/dct.html)
* http://www.explainthatstuff.com/digitalcameras.html
* http://www.hkvstar.com
* http://www.hometheatersound.com/