From 6fe8556a19c4494d4312f81c2fb7d4402b31b2eb Mon Sep 17 00:00:00 2001 From: Peter Ross Date: Tue, 1 Nov 2022 09:24:29 +1100 Subject: [PATCH] avcodec/svq1: fix interframe mean VLC symbols Fixes ticket #128. The SVQ1 interframe mean VLC symbols -128 and 128 are incorrectly swapped in our SVQ1 implementation, resulting in visible artifacts for some videos. This patch unswaps the order of these two symbols. The most noticable example of the artiacts caused by this error can be observed in https://trac.ffmpeg.org/attachment/ticket/128/svq1_set.7z '352_288_k_50.mov'. The artifacts are not observed when using the reference decoder (QuickTime 7.7.9 x86 binary). As a result of this patch, the reference data for the fate-svq1 test ($SAMPLES/svq1/marymary-shackles.mov) must be modified. For this file, our decoder output is now bitwise identical to the reference decoder. I have tested patch with various other samples and they are all now bitwise identical. --- libavcodec/svq1_vlc.h | 4 ++-- tests/ref/fate/svq1 | 22 +++++++++++----------- 2 files changed, 13 insertions(+), 13 deletions(-) diff --git a/libavcodec/svq1_vlc.h b/libavcodec/svq1_vlc.h index 06e3509e4d..5c27928c2a 100644 --- a/libavcodec/svq1_vlc.h +++ b/libavcodec/svq1_vlc.h @@ -167,7 +167,7 @@ const uint16_t ff_svq1_inter_mean_vlc[512][2] = { { 0xA0, 22 }, { 0xA1, 22 }, { 0xA2, 22 }, { 0xA3, 22 }, { 0xA4, 22 }, { 0xA5, 22 }, { 0xA6, 22 }, { 0xA7, 22 }, { 0xA8, 22 }, { 0xA9, 22 }, { 0xAA, 22 }, { 0xAB, 22 }, - { 0x7F, 22 }, { 0x8F, 21 }, { 0xAC, 22 }, { 0xAD, 22 }, + { 0x8E, 21 }, { 0x8F, 21 }, { 0xAC, 22 }, { 0xAD, 22 }, { 0xAE, 22 }, { 0xAF, 22 }, { 0xB0, 22 }, { 0xB1, 22 }, { 0x53, 20 }, { 0x90, 21 }, { 0xB2, 22 }, { 0x91, 21 }, { 0xB3, 22 }, { 0xB4, 22 }, { 0x54, 20 }, { 0xB5, 22 }, @@ -231,7 +231,7 @@ const uint16_t ff_svq1_inter_mean_vlc[512][2] = { { 0x87, 21 }, { 0x4F, 20 }, { 0x35, 19 }, { 0x4E, 20 }, { 0x33, 19 }, { 0x32, 19 }, { 0x4D, 20 }, { 0x4C, 20 }, { 0x83, 22 }, { 0x4B, 20 }, { 0x81, 22 }, { 0x80, 22 }, - { 0x8E, 21 }, { 0x7E, 22 }, { 0x7D, 22 }, { 0x84, 21 }, + { 0x7F, 22 }, { 0x7E, 22 }, { 0x7D, 22 }, { 0x84, 21 }, { 0x8D, 21 }, { 0x7A, 22 }, { 0x79, 22 }, { 0x4A, 20 }, { 0x77, 22 }, { 0x76, 22 }, { 0x89, 21 }, { 0x74, 22 }, { 0x73, 22 }, { 0x72, 22 }, { 0x49, 20 }, { 0x70, 22 }, diff --git a/tests/ref/fate/svq1 b/tests/ref/fate/svq1 index d53e2952e4..0b0948cce6 100644 --- a/tests/ref/fate/svq1 +++ b/tests/ref/fate/svq1 @@ -24,19 +24,19 @@ 0, 18, 18, 1, 21600, 0x8d5b2ad0 0, 19, 19, 1, 21600, 0xe67128e6 0, 20, 20, 1, 21600, 0xb7bf613e -0, 21, 21, 1, 21600, 0xefd0f51b -0, 22, 22, 1, 21600, 0x31b7da59 +0, 21, 21, 1, 21600, 0xf697fa3e +0, 22, 22, 1, 21600, 0x5b6ede88 0, 23, 23, 1, 21600, 0x7a84a8f7 0, 24, 24, 1, 21600, 0x0351ad27 -0, 25, 25, 1, 21600, 0xed6f434d -0, 26, 26, 1, 21600, 0x0e771127 -0, 27, 27, 1, 21600, 0x37bf0b95 -0, 28, 28, 1, 21600, 0x30e10a77 -0, 29, 29, 1, 21600, 0x1a48288a -0, 30, 30, 1, 21600, 0xf43c6770 -0, 31, 31, 1, 21600, 0x3c43ae68 -0, 32, 32, 1, 21600, 0x04dc0949 -0, 33, 33, 1, 21600, 0x7920758d +0, 25, 25, 1, 21600, 0x57b547c2 +0, 26, 26, 1, 21600, 0xbb9e1558 +0, 27, 27, 1, 21600, 0xcb470f6b +0, 28, 28, 1, 21600, 0xeb100de0 +0, 29, 29, 1, 21600, 0x089c2bf0 +0, 30, 30, 1, 21600, 0xe27b6a42 +0, 31, 31, 1, 21600, 0xbfe2b11b +0, 32, 32, 1, 21600, 0xd9ca0bb5 +0, 33, 33, 1, 21600, 0x12fe783c 0, 34, 34, 1, 21600, 0x6c12bab5 0, 35, 35, 1, 21600, 0x1ac23706 0, 36, 36, 1, 21600, 0x7a95cb5f