[FFmpeg-trac] #4746(avcodec:new): prores alpha blending results in opaque rectangle
FFmpeg
trac at avcodec.org
Fri Jul 31 15:58:38 CEST 2015
#4746: prores alpha blending results in opaque rectangle
-------------------------------------+-------------------------------------
Reporter: | Owner:
projectsymphony | Status: new
Type: defect | Component: avcodec
Priority: normal | Resolution:
Version: git-master | Blocked By:
Keywords: | Reproduced by developer: 0
Blocking: |
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
Comment (by projectsymphony):
yes I agree with gjdfgh, and what about conversion using ffmpeg?
It's a well known behaviour that when alpha is converted to an opaque
format it is blended with black by default
btw, using the provided option with ffmpeg results in an infinite
conversion
{{{
ffmpeg -i proresalphablock.mov -vf
'scale[in],color=black:1920x1080[back],[back][in]overlay' -pix_fmt yuv420p
output.mov
ffmpeg version N-73640-gae4c9dd Copyright (c) 2000-2015 the FFmpeg
developers
built with Apple LLVM version 6.0 (clang-600.0.57) (based on LLVM
3.5svn)
configuration: --cc=clang --enable-debug --disable-optimizations
--disable-yasm --disable-asm --enable-libfdk-aac --enable-version3
--enable-nonfree --enable-gpl --disable-doc --enable-libmp3lame --enable-
openssl --enable-libfreetype --enable-avresample --enable-libopenjpeg
--enable-libx264
libavutil 54. 28.100 / 54. 28.100
libavcodec 56. 47.100 / 56. 47.100
libavformat 56. 40.100 / 56. 40.100
libavdevice 56. 4.100 / 56. 4.100
libavfilter 5. 21.100 / 5. 21.100
libavresample 2. 1. 0 / 2. 1. 0
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 2.100 / 1. 2.100
libpostproc 53. 3.100 / 53. 3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'proresalphablock.mov':
Metadata:
major_brand : qt
minor_version : 512
compatible_brands: qt
creation_time : 2015-07-09 05:29:21
encoder : Lavf56.21.0
Duration: 00:00:09.43, start: 0.031833, bitrate: 13066 kb/s
Stream #0:0(eng): Video: prores (ap4h / 0x68347061), yuva444p10le,
1920x1080, 13066 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 24k tbc (default)
Metadata:
creation_time : 2015-07-09 05:29:21
handler_name : DataHandler
encoder : Apple ProRes 4444
[libx264 @ 0x7fe10c03ce00] using SAR=1/1
[libx264 @ 0x7fe10c03ce00] using cpu capabilities: MMX2 SSE2Fast SSSE3
SSE4.2 AVX FMA3 AVX2 LZCNT BMI2
[libx264 @ 0x7fe10c03ce00] profile High, level 4.0
[libx264 @ 0x7fe10c03ce00] 264 - core 148 r2538+33M bff0ecd - H.264/MPEG-4
AVC codec - Copyleft 2003-2015 - http://www.videolan.org/x264.html -
options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7
psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1
8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12
lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0
bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1
b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25
scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0
qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mov, to 'output.mov':
Metadata:
major_brand : qt
minor_version : 512
compatible_brands: qt
encoder : Lavf56.40.100
Stream #0:0(eng): Video: h264 (libx264) (avc1 / 0x31637661), yuv420p,
1920x1080 [SAR 1:1 DAR 16:9], q=-1--1, 25 fps, 12800 tbn, 25 tbc (default)
Metadata:
creation_time : 2015-07-09 05:29:21
handler_name : DataHandler
encoder : Lavc56.47.100 libx264
Stream mapping:
Stream #0:0 -> #0:0 (prores (native) -> h264 (libx264))
Press [q] to stop, [?] for help
[..]
frame=34281 fps= 48 q=28.0 size= 2458kB time=00:22:48.92 bitrate=
14.7kbits/
}}}
I had to stop it manually, but this is probably a separate bug.
--
Ticket URL: <https://trac.ffmpeg.org/ticket/4746#comment:9>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker
More information about the FFmpeg-trac
mailing list