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Revolution of Open-source and film making towards open film making
6 octobre 2011, par
Mis à jour : Juillet 2013
Langue : English
Type : Texte
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Si vous souhaitez utiliser cette archive pour une installation en mode ferme, il vous faudra également procéder à d’autres modifications (...) -
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25 avril 2011, parMediaSPIP 0.1 beta is the first version of MediaSPIP proclaimed as "usable".
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Sur d’autres sites (12836)
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FFMPEG - rewarp MPEGDash to MP4 changes audio bitrate mode
30 juin 2022, par Matthieu DucorpsI'm rewrapping some MPEGDash to MP4 wrapper and some files are outputed with variable audio bitrate where others with constant bitrate,and both sources looks exactly the same.


For reference :


I'm using FFMPEG 5.0 for the rewrapping


ffmpeg version 5.0-full_build-www.gyan.dev Copyright (c) 2000-2022 the FFmpeg developers
 built with gcc 11.2.0 (Rev5, Built by MSYS2 project)
 configuration: --enable-gpl --enable-version3 --enable-static --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-bzlib --enable-lzma --enable-libsnappy --enable-zlib --enable-librist --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca --enable-sdl2 --enable-libdav1d --enable-libdavs2 --enable-libuavs3d --enable-libzvbi --enable-librav1e --enable-libsvtav1 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs2 --enable-libxvid --enable-libaom --enable-libopenjpeg --enable-libvpx --enable-mediafoundation --enable-libass --enable-frei0r --enable-libfreetype --enable-libfribidi --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-libshaderc --enable-vulkan --enable-libplacebo --enable-opencl --enable-libcdio --enable-libgme --enable-libmodplug --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libshine --enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc --enable-libilbc --enable-libgsm --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-ladspa --enable-libbs2b --enable-libflite --enable-libmysofa --enable-librubberband --enable-libsoxr --enable-chromaprint
 libavutil 57. 17.100 / 57. 17.100
 libavcodec 59. 18.100 / 59. 18.100
 libavformat 59. 16.100 / 59. 16.100
 libavdevice 59. 4.100 / 59. 4.100
 libavfilter 8. 24.100 / 8. 24.100
 libswscale 6. 4.100 / 6. 4.100
 libswresample 4. 3.100 / 4. 3.100
 libpostproc 56. 3.100 / 56. 3.100


And MediaInfo 22.09 to check the medias.




I'm using this command to rewrap the media :


ffmpeg.exe -y -i MPEGDash.mpd -map 0:v -map 0:a -c copy OutFile.mp4


This source MPEGDASH with constant audio bitrate


General
Complete name : \\Constant\PROXY\A0002_30sec\MPEGDash_A0002_30sec.mpd
Format : DASH MPD
File size : 4.14 MiB
Duration : 30 s 80 ms
Overall bit rate mode : Constant
Overall bit rate : 1 154 kb/s

Video
ID : 0-1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L3.1
Format settings : CABAC / 2 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 2 frames
Format settings, GOP : M=3, N=30
Muxing mode : dash
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 30 s 30 ms
Bit rate mode : Constant
Bit rate : 640 kb/s
Width : 640 pixels
Height : 360 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 29.970 (30000/1001) FPS
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.093
Stream size : 2.28 MiB (55%)
Language : English
Encoded date : UTC 2022-06-30 08:20:16
Tagged date : UTC 2022-06-30 08:20:16
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Source : V0_360p_640000/V0_360p_640000_init.mp4
Codec configuration box : avcC

Audio #1
ID : 160-1
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Muxing mode : dash
Codec ID : mp4a-40-2
Duration : 30 s 80 ms
Bit rate mode : Constant
Bit rate : 128 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 460 KiB (11%)
Language : English
Encoded date : UTC 2022-06-30 08:20:16
Tagged date : UTC 2022-06-30 08:20:16
Source : A0_48000_128000/A0_48000_128000_init.mp4

Audio #2
ID : 161-1
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Muxing mode : dash
Codec ID : mp4a-40-2
Duration : 30 s 80 ms
Bit rate mode : Constant
Bit rate : 128 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 460 KiB (11%)
Language : English
Encoded date : UTC 2022-06-30 08:20:16
Tagged date : UTC 2022-06-30 08:20:16
Source : A1_48000_128000/A1_48000_128000_init.mp4

Audio #3
ID : 162-1
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Muxing mode : dash
Codec ID : mp4a-40-2
Duration : 30 s 80 ms
Bit rate mode : Constant
Bit rate : 128 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 460 KiB (11%)
Language : English
Encoded date : UTC 2022-06-30 08:20:16
Tagged date : UTC 2022-06-30 08:20:16
Source : A2_48000_128000/A2_48000_128000_init.mp4

Audio #4
ID : 163-1
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Muxing mode : dash
Codec ID : mp4a-40-2
Duration : 30 s 80 ms
Bit rate mode : Constant
Bit rate : 128 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 460 KiB (11%)
Language : English
Encoded date : UTC 2022-06-30 08:20:16
Tagged date : UTC 2022-06-30 08:20:16
Source : A3_48000_128000/A3_48000_128000_init.mp4


Has the expected output with constant audio bitrate on the MP4


General
Complete name : \\Constant\PROXY\A0002_30sec\A0002_30sec.mp4
Format : MPEG-4
Format profile : Base Media
Codec ID : isom (isom/iso2/avc1/mp41)
File size : 4.13 MiB
Duration : 30 s 96 ms
Overall bit rate mode : Constant
Overall bit rate : 1 152 kb/s
Movie name : MPEGDash_A0002_30sec.mpd
Writing application : Lavf59.16.100

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L3.1
Format settings : CABAC / 2 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 2 frames
Format settings, GOP : M=3, N=30
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 30 s 96 ms
Source duration : 29 s 997 ms
Bit rate mode : Constant
Bit rate : 590 kb/s
Nominal bit rate : 640 kb/s
Maximum bit rate : 636 kb/s
Width : 640 pixels
Height : 360 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 29.970 (30000/1001) FPS
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.085
Stream size : 2.12 MiB (51%)
Source stream size : 2.28 MiB (55%)
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
mdhd_Duration : 30030
Codec configuration box : avcC

Audio #1
ID : 2
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 30 s 80 ms
Bit rate mode : Constant
Bit rate : 125 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 460 KiB (11%)
Language : English
Default : Yes
Alternate group : 1

Audio #2
ID : 3
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 30 s 80 ms
Bit rate mode : Constant
Bit rate : 125 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 460 KiB (11%)
Language : English
Default : Yes
Alternate group : 2

Audio #3
ID : 4
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 30 s 80 ms
Bit rate mode : Constant
Bit rate : 125 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 460 KiB (11%)
Language : English
Default : Yes
Alternate group : 3

Audio #4
ID : 5
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 30 s 80 ms
Bit rate mode : Constant
Bit rate : 125 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 460 KiB (11%)
Language : English
Default : Yes
Alternate group : 4


But this source MPEGDASH which has the same characteristics :


General
Complete name : \\Variable\PROXY\A0005_30sec\MPEGDash_A0005_30sec.mpd
Format : DASH MPD
File size : 4.15 MiB
Duration : 30 s 80 ms
Overall bit rate mode : Constant
Overall bit rate : 1 157 kb/s

Video
ID : 0-1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L3.1
Format settings : CABAC / 2 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 2 frames
Format settings, GOP : M=3, N=30
Muxing mode : dash
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 30 s 30 ms
Bit rate mode : Constant
Bit rate : 640 kb/s
Width : 640 pixels
Height : 360 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 29.970 (30000/1001) FPS
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.093
Stream size : 2.29 MiB (55%)
Language : English
Encoded date : UTC 2022-06-30 08:24:03
Tagged date : UTC 2022-06-30 08:24:03
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Source : V0_360p_640000/V0_360p_640000_init.mp4
Codec configuration box : avcC

Audio #1
ID : 160-1
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Muxing mode : dash
Codec ID : mp4a-40-2
Duration : 30 s 80 ms
Bit rate mode : Constant
Bit rate : 128 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 461 KiB (11%)
Language : English
Encoded date : UTC 2022-06-30 08:24:03
Tagged date : UTC 2022-06-30 08:24:03
Source : A0_48000_128000/A0_48000_128000_init.mp4

Audio #2
ID : 161-1
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Muxing mode : dash
Codec ID : mp4a-40-2
Duration : 30 s 80 ms
Bit rate mode : Constant
Bit rate : 128 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 460 KiB (11%)
Language : English
Encoded date : UTC 2022-06-30 08:24:03
Tagged date : UTC 2022-06-30 08:24:03
Source : A1_48000_128000/A1_48000_128000_init.mp4

Audio #3
ID : 162-1
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Muxing mode : dash
Codec ID : mp4a-40-2
Duration : 30 s 80 ms
Bit rate mode : Constant
Bit rate : 128 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 460 KiB (11%)
Language : English
Encoded date : UTC 2022-06-30 08:24:03
Tagged date : UTC 2022-06-30 08:24:03
Source : A2_48000_128000/A2_48000_128000_init.mp4

Audio #4
ID : 163-1
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Muxing mode : dash
Codec ID : mp4a-40-2
Duration : 30 s 80 ms
Bit rate mode : Constant
Bit rate : 128 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 460 KiB (11%)
Language : English
Encoded date : UTC 2022-06-30 08:24:03
Tagged date : UTC 2022-06-30 08:24:03
Source : A3_48000_128000/A3_48000_128000_init.mp4


Has this output where the MP4 have the first audio with variable bitrate


General
Complete name : \\Variable\PROXY\A0005_30sec\A0005_30sec.mp4
Format : MPEG-4
Format profile : Base Media
Codec ID : isom (isom/iso2/avc1/mp41)
File size : 4.14 MiB
Duration : 30 s 96 ms
Overall bit rate mode : Variable
Overall bit rate : 1 155 kb/s
Movie name : MPEGDash_A0005_30sec.mpd
Writing application : Lavf59.16.100

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L3.1
Format settings : CABAC / 2 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 2 frames
Format settings, GOP : M=3, N=30
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 30 s 96 ms
Source duration : 29 s 997 ms
Bit rate mode : Constant
Bit rate : 593 kb/s
Nominal bit rate : 640 kb/s
Maximum bit rate : 640 kb/s
Width : 640 pixels
Height : 360 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 29.970 (30000/1001) FPS
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.086
Stream size : 2.13 MiB (51%)
Source stream size : 2.29 MiB (55%)
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
mdhd_Duration : 30030
Codec configuration box : avcC

Audio #1
ID : 2
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 30 s 80 ms
Bit rate mode : Variable
Bit rate : 126 kb/s
Maximum bit rate : 128 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 461 KiB (11%)
Language : English
Default : Yes
Alternate group : 1

Audio #2
ID : 3
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 30 s 80 ms
Bit rate mode : Constant
Bit rate : 125 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 460 KiB (11%)
Language : English
Default : Yes
Alternate group : 2

Audio #3
ID : 4
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 30 s 80 ms
Bit rate mode : Constant
Bit rate : 125 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 460 KiB (11%)
Language : English
Default : Yes
Alternate group : 3

Audio #4
ID : 5
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 30 s 80 ms
Bit rate mode : Constant
Bit rate : 125 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 460 KiB (11%)
Language : English
Default : Yes
Alternate group : 4


Maybe I'm missing something but,I don't see what.


-
France rules Google Analytics non-compliant with GDPR
11 février 2022, par Erin — PrivacyBreaking news : The French Data Protection Agency, CNIL (Commission nationale de l’informatique et des libertés), has concluded that the use of Google Analytics is illegal under GDPR. The CNIL has begun issuing formal notices to website managers using Google Analytics.
This follows the January 2022 Austrian Data Protection Authority’s decision to declare Google Analytics illegal to use under GDPR.
Google Analytics GDPR breaches continue to spread through the EU
Since the invalidation of the Privacy Shield framework, an agreement between the EU and US that allowed the transfer of data to certified US companies, the CNIL and other EU data protection authorities have received numerous complaints regarding data transfers collected during visits to websites using Google Analytics.
"It’s interesting to see that the different European Data Protection Authorities all come to the same conclusion : the use of Google Analytics is illegal. There is a European task force and we assume that this action is coordinated and other authorities will decide similarly."
About the CNIL’s decision
In this model case, the CNIL has found that an unnamed website’s use of Google Analytics is non-compliant with GDPR because it had breached Article 44 which prohibits the transfer of personal data beyond the EU, unless the recipient country can prove adequate data protection.
Under the GDPR, personal data covers a range of identifiers including email address, race, gender, phone number to name a few, but the less obvious identifiers include IP addresses or cookie IDs, for instance.
The CNIL’s decision was based on the fact that the US does not meet GDPR sufficient levels of data protection as a result of US surveillance laws. Therefore, the unnamed website’s use of Google Analytics created risks for their website visitors when their personal data was exported to the US.
At the time of writing, it is unknown if the CNIL has issued a fine for the GDPR breach. However, the website manager of the unnamed website has been ordered by the CNIL to comply with the GDPR and, if necessary, stop using Google Analytics under the current conditions.
"One thing we’re certain of is that these decisions will continue to roll out throughout the EU and potentially beyond.
Other countries are imposing their own privacy regulations that closely mirror the GDPR like Brazil’s General Data Protection Law (LGPD), India’s Data Protection Bill, New Zealand’s Privacy Act and Canada’s Personal Information Protection and Electronic Documents Act (PIPEDA) to name a few.”
The CNIL offers an evaluation programme to help website managers determine whether web analytics solutions are exempt from collecting data prior to users’ agreement to opt-in through consent screens. Matomo, for instance, is a leading Google Analytics alternative that has been recommended by CNIL and is exempt from tracking consent.
five5stardesign via Twitter English translation : “This is why I anticipated this announcement, gradually moving the analytics of my sites to @matomo_org since several weeks !
“The @CNIL believes that the use of @googleanalytics is a violation of #GDPR”
Immediate action required for Google Analytics users
The CNIL and other EU-based data protection authorities have made their stance on Google Analytics clear and inaction will likely result in fines, which under the GDPR, can be up to €20 million or 4% of the organisation’s global turnover – whichever is higher.
Based on the CNIL’s formal notice to the model case’s website manager, Google Analytics users should take immediate action to remove any chances of personal data being transferred to the US or find a Google Analytics alternative that is GDPR compliant.
Virginie Debuisson via Twitter English translation : “The CNIL considers that the use of Google Analytics is a violation of the GDPR. I use @matomo_org and I welcome it *winking face* It will squeal tires among growthackers who are slaughtering. Opportunity to look at alternative tools”
Ready to begin your journey to GDPR compliance with Matomo ? Start your 21-day free trial now (no credit card required) and take advantage of our Google Analytics importer so you don’t lose any of your historical data.
What does this mean for Matomo users ?
As the GDPR continues to evolve, our users can rest assured that Matomo will be at the forefront of these changes. With Matomo Cloud, all data is stored in the EU or in your country of choice when you self-host on your own servers with Matomo On-Premise.
Conclusion
Google is in the EU’s crosshairs and organisations that continue to use their tools will be the one’s left to clean up the mess – not Google. Now is the time to act. Search for a Google Analytics alternative and close your compliance gaps today.
Join over 1 million other websites using Matomo now. Give Matomo a try with a 21-day free trial – no credit card required.
Contact details for media :
For quotes or interviews, please email marketing@matomo.org
-
FFMPEG Api conversion from YUV420P to RGB produces strange output
20 novembre 2024, par fasc8I'm using the FFMPEG Api in Rust to get RGB images from video files.


While some videos work correct and I get the frames back as expected, some work not. Or at least the result is not the way I expected it to be.


The code I use in Rust :


ffmpeg::init().unwrap();

let in_ctx = input(&Path::new(source)).unwrap();
let input = in_ctx
 .streams()
 .best(Type::Video)
 .ok_or(ffmpeg::Error::StreamNotFound)?;

let decoder = input.codec().decoder().video()?;

let scaler = Context::get(
 decoder.format(),
 decoder.width(),
 decoder.height(),
 Pixel::RGB24,
 decoder.width(),
 decoder.height(),
 Flags::FULL_CHR_H_INT | Flags::ACCURATE_RND,
)?; // <--- Is basically sws_getContext

// later to get the actual frame
let mut decoded = Video::empty();
if self.decoder.receive_frame(&mut decoded).is_ok() {
 let mut rgb_frame = Video::empty();
 self.scaler.run(&decoded, &mut rgb_frame)?; // <--- Does sws_scale
 println!("Converted Pixel Format: {}", rgb_frame.format() as i32);
 Ok(Some(rgb_frame))
}


Which should roughly translate to C like so :


// Get the context and video stream
SwsContext * ctx = sws_getContext(imgWidth, imgHeight,
 imgFormat, imgWidth, imgHeight,
 AV_PIX_FMT_RGB24, 0, 0, 0, 0);
sws_scale(ctx, decoded.data, decoded.linesize, 0, decoded.height, rgb_frame.data, rbg_frame.linesize);


And like I said earlier, sometimes it works fine and I get the expected frame back. But sometimes I get something like this :
Weird result image


I saved the images as .ppm files for quick visual comparison. I used this method, which basically writes the bytes to a file with a simple .ppm header :


fn save_file(frame: &Video, index: usize) -> std::result::Result<(), std::io::Error> 
{
 let mut file = File::create(format!("frame{}.ppm", index))?;
 file.write_all(format!("P6\n{} {}\n255\n", frame.width(), frame.height()).as_bytes())?;
 file.write_all(frame.data(0))?;
 Ok(())
}


Here you can see that on the left side there is a good image result vs. on the right side there is a bad image result.
Comparison of the .ppm files


To come to the question now :


Why is this happening. I tested everything on my side and the only thing left is ffmpeg conversion. FFMPEG seems to convert these two test files differently even though it reports YUV420P as format for both. I cannot figure out what the difference may be...


Here the info for the two video files i used :


Good video file :


General
Complete name : /mnt/smb/Snapchat-174933781.mp4
Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42 (isom/mp42)
File size : 1.90 MiB
Duration : 9 s 612 ms
Overall bit rate : 1 661 kb/s
Encoded date : UTC 2021-07-28 22:09:36
Tagged date : UTC 2021-07-28 22:09:36
eng : -180.00

Video
ID : 512
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L3.1
Format settings : CABAC / 1 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 1 frame
Format settings, GOP : M=1, N=30
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 9 s 598 ms
Bit rate : 1 597 kb/s
Width : 480 pixels
Height : 944 pixels
Display aspect ratio : 0.508
Frame rate mode : Variable
Frame rate : 29.797 FPS
Minimum frame rate : 15.000 FPS
Maximum frame rate : 30.000 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.118
Stream size : 1.83 MiB (96%)
Title : Snap Video
Language : English
Encoded date : UTC 2021-07-28 22:09:36
Tagged date : UTC 2021-07-28 22:09:36
Color range : Full
colour_range_Original : Limited
Color primaries : BT.709
Transfer characteristics : BT.601
transfer_characteristics_Original : BT.709
Matrix coefficients : BT.709
Codec configuration box : avcC

Audio
ID : 256
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 9 s 612 ms
Bit rate mode : Constant
Bit rate : 62.0 kb/s
Channel(s) : 1 channel
Channel layout : C
Sampling rate : 44.1 kHz
Frame rate : 43.066 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 73.3 KiB (4%)
Title : Snap Audio
Language : English
Encoded date : UTC 2021-07-28 22:09:36
Tagged date : UTC 2021-07-28 22:09:36


Bad video file :


General
Complete name : /mnt/smb/Snapchat-1989594918.mp4
Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42 (isom/mp42)
File size : 2.97 MiB
Duration : 6 s 313 ms
Overall bit rate : 3 948 kb/s
Encoded date : UTC 2019-07-11 06:43:04
Tagged date : UTC 2019-07-11 06:43:04
com.android.version : 9

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Baseline@L3.1
Format settings : 1 Ref Frames
Format settings, CABAC : No
Format settings, Reference frames : 1 frame
Format settings, GOP : M=1, N=30
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 6 s 313 ms
Bit rate : 3 945 kb/s
Width : 496 pixels
Height : 960 pixels
Display aspect ratio : 0.517
Frame rate mode : Variable
Frame rate : 29.306 FPS
Minimum frame rate : 19.767 FPS
Maximum frame rate : 39.508 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.283
Stream size : 2.97 MiB (100%)
Title : VideoHandle
Language : English
Encoded date : UTC 2019-07-11 06:43:04
Tagged date : UTC 2019-07-11 06:43:04
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Codec configuration box : avcC


Or as a diff image :


The problem is that I am not that familiar with ffmpeg yet I don't know all the quirks it has.


I hope someone can point me in the right direction.


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