[FFmpeg-trac] #7719(undetermined:closed): Extracting transparent PNGs from vp9a fails (vp8a works)
FFmpeg
trac at avcodec.org
Thu Feb 7 20:17:21 EET 2019
#7719: Extracting transparent PNGs from vp9a fails (vp8a works)
-------------------------------------+-------------------------------------
Reporter: rroller | Owner:
Type: defect | Status: closed
Priority: normal | Component:
| undetermined
Version: unspecified | Resolution: invalid
Keywords: vp9 alpha | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
Old description:
> Extracting transparent PNG files from a vp8a webm video with an alpha
> channel works. Extracting PNG files from a vp9a webm video with an alpha
> channel does not work.
>
> How to reproduce:
> With a vp8a, no issue...
> {{{
> % ffmpeg -vcodec libvpx -i vp8a.webm -pix_fmt rgba out/image_%d.png
> > produces transparent PNGs
> }}}
>
> Fails with a vp9a webm video:
> {{{
> % ffmpeg -vcodec libvpx -i vp9a.webm -pix_fmt rgba out/image_%d.png
> fmpeg version 4.1 Copyright (c) 2000-2018 the FFmpeg developers
> built with gcc 4.9.2 (Debian 4.9.2-10+deb8u2)
> configuration: --enable-gpl --enable-libx264 --enable-libx265 --enable-
> libwebp --enable-librsvg --enable-libvorbis --enable-libvpx --disable-
> network
> libavutil 56. 22.100 / 56. 22.100
> libavcodec 58. 35.100 / 58. 35.100
> libavformat 58. 20.100 / 58. 20.100
> libavdevice 58. 5.100 / 58. 5.100
> libavfilter 7. 40.101 / 7. 40.101
> libswscale 5. 3.100 / 5. 3.100
> libswresample 3. 3.100 / 3. 3.100
> libpostproc 55. 3.100 / 55. 3.100
> [libvpx @ 0x2d0c580] v1.8.0
> [libvpx @ 0x2d0c580] Invalid sync code 430042.
> [libvpx @ 0x2d0c580] Failed to decode frame: Bitstream not supported by
> this decoder
> [libvpx @ 0x2d0c580] Invalid sync code 844e49.
> [libvpx @ 0x2d0c580] Failed to decode frame: Bitstream not supported by
> this decoder
> }}}
>
> Versions:
> {{{
> ffmpeg version: 4.1 installed from source built on Debian 4.9.2-10+deb8u2
> Also tried with ffmpeg from homebrew on a mac.
> }}}
>
> Here's ffprobe output for both vids:
> {{{
> ffprobe vp8a.webm
> ffprobe version 4.1 Copyright (c) 2007-2018 the FFmpeg developers
> built with gcc 4.9.2 (Debian 4.9.2-10+deb8u2)
> configuration: --enable-gpl --enable-libx264 --enable-libx265 --enable-
> libwebp --enable-librsvg --enable-libvorbis --enable-libvpx --disable-
> network
> libavutil 56. 22.100 / 56. 22.100
> libavcodec 58. 35.100 / 58. 35.100
> libavformat 58. 20.100 / 58. 20.100
> libavdevice 58. 5.100 / 58. 5.100
> libavfilter 7. 40.101 / 7. 40.101
> libswscale 5. 3.100 / 5. 3.100
> libswresample 3. 3.100 / 3. 3.100
> libpostproc 55. 3.100 / 55. 3.100
> Input #0, matroska,webm, from 'vp8a.webm':
> Metadata:
> encoder : libwebm-0.2.1.0
> creation_time : 2019-02-07T21:34:38.000000Z
> Duration: 00:00:11.00, start: 0.000000, bitrate: 392 kb/s
> Stream #0:0(eng): Video: vp8, yuv420p(progressive), 1080x1920, SAR
> 1:1 DAR 9:16, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
> Metadata:
> alpha_mode : 1
>
> ffprobe vp9a.webm
> ffprobe version 4.1 Copyright (c) 2007-2018 the FFmpeg developers
> built with gcc 4.9.2 (Debian 4.9.2-10+deb8u2)
> configuration: --enable-gpl --enable-libx264 --enable-libx265 --enable-
> libwebp --enable-librsvg --enable-libvorbis --enable-libvpx --disable-
> network
> libavutil 56. 22.100 / 56. 22.100
> libavcodec 58. 35.100 / 58. 35.100
> libavformat 58. 20.100 / 58. 20.100
> libavdevice 58. 5.100 / 58. 5.100
> libavfilter 7. 40.101 / 7. 40.101
> libswscale 5. 3.100 / 5. 3.100
> libswresample 3. 3.100 / 3. 3.100
> libpostproc 55. 3.100 / 55. 3.100
> Input #0, matroska,webm, from 'vp9a.webm':
> Metadata:
> encoder : libwebm-0.2.1.0
> creation_time : 2019-02-07T15:31:54.000000Z
> Duration: 00:00:11.00, start: 0.000000, bitrate: 281 kb/s
> Stream #0:0(eng): Video: vp9 (Profile 0), yuv420p(tv), 1080x1920, SAR
> 1:1 DAR 9:16, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
> Metadata:
> alpha_mode : 1
> }}}
New description:
{{{
% ffmpeg -vcodec libvpx -i vp9a.webm -pix_fmt rgba out/image_%d.png
}}}
The codec's name is `libvpx-vp9`.
--
Comment (by cehoyos):
Replying to [ticket:7719 rroller]:
> Extracting transparent PNG files from a vp8a webm video with an alpha
channel works. Extracting PNG files from a vp9a webm video with an alpha
channel does not work.
>
> How to reproduce:
> With a vp8a, no issue...
> {{{
> % ffmpeg -vcodec libvpx -i vp8a.webm -pix_fmt rgba out/image_%d.png
> > produces transparent PNGs
> }}}
>
> Fails with a vp9a webm video:
> {{{
> % ffmpeg -vcodec libvpx -i vp9a.webm -pix_fmt rgba out/image_%d.png
> fmpeg version 4.1 Copyright (c) 2000-2018 the FFmpeg developers
> built with gcc 4.9.2 (Debian 4.9.2-10+deb8u2)
> configuration: --enable-gpl --enable-libx264 --enable-libx265
--enable-libwebp --enable-librsvg --enable-libvorbis --enable-libvpx
--disable-network
> libavutil 56. 22.100 / 56. 22.100
> libavcodec 58. 35.100 / 58. 35.100
> libavformat 58. 20.100 / 58. 20.100
> libavdevice 58. 5.100 / 58. 5.100
> libavfilter 7. 40.101 / 7. 40.101
> libswscale 5. 3.100 / 5. 3.100
> libswresample 3. 3.100 / 3. 3.100
> libpostproc 55. 3.100 / 55. 3.100
> [libvpx @ 0x2d0c580] v1.8.0
> [libvpx @ 0x2d0c580] Invalid sync code 430042.
> [libvpx @ 0x2d0c580] Failed to decode frame: Bitstream not supported by
this decoder
> [libvpx @ 0x2d0c580] Invalid sync code 844e49.
> [libvpx @ 0x2d0c580] Failed to decode frame: Bitstream not supported by
this decoder
> }}}
>
>
> Versions:
> {{{
> ffmpeg version: 4.1 installed from source built on Debian
4.9.2-10+deb8u2
> Also tried with ffmpeg from homebrew on a mac.
> }}}
>
>
> Here's ffprobe output for both vids:
> {{{
> ffprobe vp8a.webm
> ffprobe version 4.1 Copyright (c) 2007-2018 the FFmpeg developers
> built with gcc 4.9.2 (Debian 4.9.2-10+deb8u2)
> configuration: --enable-gpl --enable-libx264 --enable-libx265
--enable-libwebp --enable-librsvg --enable-libvorbis --enable-libvpx
--disable-network
> libavutil 56. 22.100 / 56. 22.100
> libavcodec 58. 35.100 / 58. 35.100
> libavformat 58. 20.100 / 58. 20.100
> libavdevice 58. 5.100 / 58. 5.100
> libavfilter 7. 40.101 / 7. 40.101
> libswscale 5. 3.100 / 5. 3.100
> libswresample 3. 3.100 / 3. 3.100
> libpostproc 55. 3.100 / 55. 3.100
> Input #0, matroska,webm, from 'vp8a.webm':
> Metadata:
> encoder : libwebm-0.2.1.0
> creation_time : 2019-02-07T21:34:38.000000Z
> Duration: 00:00:11.00, start: 0.000000, bitrate: 392 kb/s
> Stream #0:0(eng): Video: vp8, yuv420p(progressive), 1080x1920, SAR
1:1 DAR 9:16, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
> Metadata:
> alpha_mode : 1
>
>
> ffprobe vp9a.webm
> ffprobe version 4.1 Copyright (c) 2007-2018 the FFmpeg developers
> built with gcc 4.9.2 (Debian 4.9.2-10+deb8u2)
> configuration: --enable-gpl --enable-libx264 --enable-libx265
--enable-libwebp --enable-librsvg --enable-libvorbis --enable-libvpx
--disable-network
> libavutil 56. 22.100 / 56. 22.100
> libavcodec 58. 35.100 / 58. 35.100
> libavformat 58. 20.100 / 58. 20.100
> libavdevice 58. 5.100 / 58. 5.100
> libavfilter 7. 40.101 / 7. 40.101
> libswscale 5. 3.100 / 5. 3.100
> libswresample 3. 3.100 / 3. 3.100
> libpostproc 55. 3.100 / 55. 3.100
> Input #0, matroska,webm, from 'vp9a.webm':
> Metadata:
> encoder : libwebm-0.2.1.0
> creation_time : 2019-02-07T15:31:54.000000Z
> Duration: 00:00:11.00, start: 0.000000, bitrate: 281 kb/s
> Stream #0:0(eng): Video: vp9 (Profile 0), yuv420p(tv), 1080x1920,
SAR 1:1 DAR 9:16, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
> Metadata:
> alpha_mode : 1
> }}}
--
Ticket URL: <https://trac.ffmpeg.org/ticket/7719#comment:5>
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