February 2018 - FFmpeg-trac - lists.ffmpeg.org

Re: [FFmpeg-trac] #1693(avcodec:new): AAC Scalable Sample Rate (SSR)
by FFmpeg 15 Feb '18

15 Feb '18

#1693: AAC Scalable Sample Rate (SSR) ------------------------------------+----------------------------------- Reporter: cehoyos | Owner: Type: defect | Status: new Priority: normal | Component: avcodec Version: git-master | Resolution: Keywords: aac | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | ------------------------------------+----------------------------------- Comment (by dalecurtis): Actually now that I mention that they may be causing duration loss too. Whether or not these are also invalid I'm not sure. -- Ticket URL: <https://trac.ffmpeg.org/ticket/1693#comment:19> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker

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Re: [FFmpeg-trac] #1693(avcodec:new): AAC Scalable Sample Rate (SSR)
by FFmpeg 15 Feb '18

15 Feb '18

#1693: AAC Scalable Sample Rate (SSR) ------------------------------------+----------------------------------- Reporter: cehoyos | Owner: Type: defect | Status: new Priority: normal | Component: avcodec Version: git-master | Resolution: Keywords: aac | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | ------------------------------------+----------------------------------- Comment (by dalecurtis): The fdk errors are just gain control ones and don't result in duration loss AFAICT: [libfdk_aac @ 0xa66940] aacDecoder_DecodeFrame() failed: 400a Error while decoding stream #0:0: Unknown error occurred 400a is AAC_DEC_UNSUPPORTED_GAIN_CONTROL_DATA = 0x400A, /*!< Gain control data found but not supported. Most probably the bitstream is corrupt, or has a wrong format. */ -- Ticket URL: <https://trac.ffmpeg.org/ticket/1693#comment:18> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker

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Re: [FFmpeg-trac] #1693(avcodec:new): AAC Scalable Sample Rate (SSR)
by FFmpeg 15 Feb '18

15 Feb '18

#1693: AAC Scalable Sample Rate (SSR) ------------------------------------+----------------------------------- Reporter: cehoyos | Owner: Type: defect | Status: new Priority: normal | Component: avcodec Version: git-master | Resolution: Keywords: aac | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | ------------------------------------+----------------------------------- Comment (by heleppkes): The fdk decoder also emits a lot of errors on this clip and decodes with audible distortions (albeit different ones then the native decoder), so either the specified clip is broken or its an extremely unusual encoding. -- Ticket URL: <https://trac.ffmpeg.org/ticket/1693#comment:17> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker

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Re: [FFmpeg-trac] #1693(avcodec:new): AAC Scalable Sample Rate (SSR)
by FFmpeg 15 Feb '18

15 Feb '18

#1693: AAC Scalable Sample Rate (SSR) ------------------------------------+----------------------------------- Reporter: cehoyos | Owner: Type: defect | Status: new Priority: normal | Component: avcodec Version: git-master | Resolution: Keywords: aac | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | ------------------------------------+----------------------------------- Comment (by dalecurtis): How are you getting that 19.5 number? I'm not able to generate a shorter clip with libfdk. The SSR packets have duration, so by dropping them the ffmpeg decoded copy will by necessity be shorter. -- Ticket URL: <https://trac.ffmpeg.org/ticket/1693#comment:16> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker

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Re: [FFmpeg-trac] #1693(avcodec:new): AAC Scalable Sample Rate (SSR)
by FFmpeg 14 Feb '18

14 Feb '18

#1693: AAC Scalable Sample Rate (SSR) ------------------------------------+----------------------------------- Reporter: cehoyos | Owner: Type: defect | Status: new Priority: normal | Component: avcodec Version: git-master | Resolution: Keywords: aac | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | ------------------------------------+----------------------------------- Comment (by cehoyos): Replying to [comment:14 dalecurtis]: > ffmpeg -acodec libfdk_aac -i ssr_chrome.aac -acodec libfdk_aac out.mp4 This produces a stream here that plays for approximately 19.5 seconds, just as the original file you attached with the native decoder. I also wonder why you believe that libfdk works so much better for this sample if re-encoding to aac with libfdk produces a shorter file. -- Ticket URL: <https://trac.ffmpeg.org/ticket/1693#comment:15> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker

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Re: [FFmpeg-trac] #1693(avcodec:new): AAC Scalable Sample Rate (SSR)
by FFmpeg 14 Feb '18

14 Feb '18

#1693: AAC Scalable Sample Rate (SSR) ------------------------------------+----------------------------------- Reporter: cehoyos | Owner: Type: defect | Status: new Priority: normal | Component: avcodec Version: git-master | Resolution: Keywords: aac | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | ------------------------------------+----------------------------------- Comment (by dalecurtis): Ah, sorry I thought it was clear when I said use mp4. Here's the command line: ffmpeg -acodec libfdk_aac -i ssr_chrome.aac -acodec libfdk_aac out.mp4 -- Ticket URL: <https://trac.ffmpeg.org/ticket/1693#comment:14> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker

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Re: [FFmpeg-trac] #1693(avcodec:new): AAC Scalable Sample Rate (SSR)
by FFmpeg 14 Feb '18

14 Feb '18

#1693: AAC Scalable Sample Rate (SSR) ------------------------------------+----------------------------------- Reporter: cehoyos | Owner: Type: defect | Status: new Priority: normal | Component: avcodec Version: git-master | Resolution: Keywords: aac | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | ------------------------------------+----------------------------------- Comment (by cehoyos): Replying to [comment:12 dalecurtis]: > Yes, it's 20.08 seconds of audio. So how can I get 20 second output from the file you uploaded? -- Ticket URL: <https://trac.ffmpeg.org/ticket/1693#comment:13> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker

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Re: [FFmpeg-trac] #1693(avcodec:new): AAC Scalable Sample Rate (SSR)
by FFmpeg 14 Feb '18

14 Feb '18

#1693: AAC Scalable Sample Rate (SSR) ------------------------------------+----------------------------------- Reporter: cehoyos | Owner: Type: defect | Status: new Priority: normal | Component: avcodec Version: git-master | Resolution: Keywords: aac | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | ------------------------------------+----------------------------------- Comment (by dalecurtis): Yes, it's 20.08 seconds of audio. The duration information isn't accurate when you write to .aac container, if you use out.mp4 instead you'll see the true accurate duration: $ ffmpeg -i out.mp4 ffmpeg version N-89956-gcaa4bd7a9f Copyright (c) 2000-2018 the FFmpeg developers built with clang version 6.0.0 (trunk 321529) configuration: --enable-shared --enable-nonfree --enable-gpl --cc=clang --ld=clang --enable-libfdk-aac libavutil 56. 7.100 / 56. 7.100 libavcodec 58. 9.100 / 58. 9.100 libavformat 58. 7.100 / 58. 7.100 libavdevice 58. 0.101 / 58. 0.101 libavfilter 7. 11.101 / 7. 11.101 libswscale 5. 0.101 / 5. 0.101 libswresample 3. 0.101 / 3. 0.101 libpostproc 55. 0.100 / 55. 0.100 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'out.mp4': Metadata: major_brand : isom minor_version : 512 compatible_brands: isomiso2mp41 encoder : Lavf58.7.100 Duration: 00:00:20.08, start: 0.000000, bitrate: 132 kb/s Stream #0:0(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 130 kb/s (default) Metadata: handler_name : SoundHandler At least one output file must be specified -- Ticket URL: <https://trac.ffmpeg.org/ticket/1693#comment:12> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker

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Re: [FFmpeg-trac] #1693(avcodec:new): AAC Scalable Sample Rate (SSR)
by FFmpeg 14 Feb '18

14 Feb '18

#1693: AAC Scalable Sample Rate (SSR) ------------------------------------+----------------------------------- Reporter: cehoyos | Owner: Type: defect | Status: new Priority: normal | Component: avcodec Version: git-master | Resolution: Keywords: aac | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | ------------------------------------+----------------------------------- Comment (by cehoyos): Replying to [comment:9 dalecurtis]: > This became an issue in Chrome because we stopped silently dropping these packets and instead started emitting an error. Skipping the SSR packet (like we did in M63 and below) leads to an accumulation of ~1 seconds of audio loss every 10 seconds. If I understand correctly, you are saying that the sample you uploaded that plays for approximately 19.5 seconds with current FFmpeg, is supposed to play longer. > Given the volume of complaints quite a few folks have been silently losing their audio over the years. The workaround for now is to re-encode with libfdk_aac which can parse the SSR packets: > > ./ffmpeg -acodec libfdk_aac -i <file> -acodec libfdk_aac -vcodec copy <out file> I tested the following command line: $ ffmpeg -acodec libfdk_aac -i ssr_chrome.aac -acodec libfdk_aac out.aac The output file plays for approximately 17 seconds: What did I misunderstand? -- Ticket URL: <https://trac.ffmpeg.org/ticket/1693#comment:11> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker

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#7020(avcodec:new): Distorted frames at stream start with Mediacodec in PORTRAIT VIDEOS
by FFmpeg 14 Feb '18

14 Feb '18

#7020: Distorted frames at stream start with Mediacodec in PORTRAIT VIDEOS ------------------------------------+---------------------------------- Reporter: kaushal86 | Type: defect Status: new | Priority: normal Component: avcodec | Version: 3.4 Keywords: Mediacodec | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | ------------------------------------+---------------------------------- Summary of the bug: I compiles FFmpeg with Mediacodec support and tried to play a video with SDL. It plays fine but when I used portrait video, the initial frames (at start) are distorted and then it resumes normal playing. It happens everytime the same portrait video is played (in loop) or a new portrait video is loaded. No issue with landscape videos. -- Ticket URL: <https://trac.ffmpeg.org/ticket/7020> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker

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