Bug 223 - MPEG1/2 optimizations
Summary: MPEG1/2 optimizations
Status: RESOLVED FIXED
Alias: None
Product: Libre-SOC's first SoC
Classification: Unclassified
Component: Source Code (show other bugs)
Version: unspecified
Hardware: PC Linux
: --- enhancement
Assignee: Jacob Lifshay
URL:
Depends on: 933
Blocks: 137
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Reported: 2020-03-13 09:56 GMT by cand
Modified: 2022-10-14 10:55 BST (History)
3 users (show)

See Also:
NLnet milestone: NLNet.2019.10.031.Video
total budget (EUR) for completion of task and all subtasks: 1500
budget (EUR) for this task, excluding subtasks' budget: 1500
parent task for budget allocation: 137
child tasks for budget allocation:
The table of payments (in EUR) for this task; TOML format:
lkcl = { amount = 750, submitted = 2022-10-04, paid = 2022-10-11 } [jacob] amount = 750 submitted = 2022-10-03 paid = 2022-10-14

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Description cand 2020-03-13 09:56:29 GMT 
Optimizing MPEG1/2 code in ffmpeg with new instructions.
Comment 1 Luke Kenneth Casson Leighton 2022-09-24 18:31:54 BST 
the algorithm chosen to optimise is huffman decode.
as part of adding pcdec, implementation of data-dependent
fail-first was required.
https://git.libre-soc.org/?p=openpower-isa.git;a=commitdiff;h=127e73917f8988800fd50560f4853b7235080229;hp=628ec4448c306d45c77fba299835c654cb1a8ef6
Comment 2 Jacob Lifshay 2022-10-03 23:37:08 BST 
Marking this resolved -- pcdec. is working and has working unit tests -- see #933.

#933 will stay open because pcdec. still has some design that needs to be done -- mostly deciding which exact set of 4 modes are needed.

See https://bugs.libre-soc.org/show_bug.cgi?id=933#c38 for relevance to MPEG1/2 (MP3 specifically for that comment)
Comment 3 Jacob Lifshay 2022-10-03 23:39:36 BST 
(In reply to Jacob Lifshay from comment #2)
> Marking this resolved -- pcdec. is working and has working unit tests -- see
> #933.
> 
> #933 will stay open because pcdec. still has some design that needs to be
> done -- mostly deciding which exact set of 4 modes are needed.
> 
> See https://bugs.libre-soc.org/show_bug.cgi?id=933#c38 for relevance to
> MPEG1/2 (MP3 specifically for that comment)

afaict MPEG1/2 video uses huffman decode/encode too.