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• Getting a lot of Tail Silence when combining an image and audio into mp4 movie

  1er avril 2023, par Meryan

  As it can be seen from this snapshot the audio HELLO.mp3 combined with bitmap HELLO.jpg produced a movie HELLO_aac.mp4 that has a huge amount of tail silence

  


  

  


  The command line I was helped to put together is the following

  


  ======================== 
IN_FILES=-i ".\HELLO.JPG" -i ".\HELLO.MP3"    
OUT_FILE=".\HELLO_aac.MP4"   
EXE="S:\_BINS\FFmpeg 4.2.1 20200112\bin\ffmpeg.exe"  
OPTIONS= -loop 1   -i ".\HELLO.JPG" -i ".\HELLO.MP3"    -vf "scale=-1:1080,pad=1920:1080:(1920-iw)/2:(1080-ih)/2,setsar=1"  -c:v libx264 -profile:v main -pix_fmt yuv420p -r 24 -video_track_timescale 24000    -c:a aac    -shortest -y ".\HELLO_aac.MP4"     
======================== 



  


  Here is the captured output from FFmpeg

  


  ffmpeg version git-2020-01-10-3d894db Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9.2.1 (GCC) 20191125
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
  libavutil      56. 38.100 / 56. 38.100
  libavcodec     58. 65.103 / 58. 65.103
  libavformat    58. 35.101 / 58. 35.101
  libavdevice    58.  9.103 / 58.  9.103
  libavfilter     7. 70.101 /  7. 70.101
  libswscale      5.  6.100 /  5.  6.100
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Input #0, image2, from '.\HELLO.JPG':
  Duration: 00:00:00.04, start: 0.000000, bitrate: 23923 kb/s
    Stream #0:0: Video: mjpeg (Baseline), yuvj420p(pc, bt470bg/unknown/unknown), 1600x1200 [SAR 120:120 DAR 4:3], 25 fps, 25 tbr, 25 tbn, 25 tbc
[mp3 @ 000002019015d4c0] Estimating duration from bitrate, this may be inaccurate
Input #1, mp3, from '.\HELLO.MP3':
  Metadata:
    genre           : Blues
    id3v2_priv.XMP  : <?xpacket begin="\xef\xbb\xbf" id="W5M0MpCehiHzreSzNTczkc9d"?>\x0a\x0a \x0a  s
    Stream #1:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (mjpeg (native) -> h264 (libx264))
  Stream #1:0 -> #0:1 (mp3 (mp3float) -> aac (native))
Press [q] to stop, [?] for help
[swscaler @ 0000020190b10380] deprecated pixel format used, make sure you did set range correctly
[swscaler @ 0000020190b10380] Warning: data is not aligned! This can lead to a speed loss
[libx264 @ 0000020190759300] using SAR=1/1
[libx264 @ 0000020190759300] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 0000020190759300] profile Main, level 4.0, 4:2:0, 8-bit
[libx264 @ 0000020190759300] 264 - core 158 - H.264/MPEG-4 AVC codec - Copyleft 2003-2019 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x1:0x111 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=34 lookahead_threads=5 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=24 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, mp4, to '.\HELLO_aac.MP4':
  Metadata:
    encoder         : Lavf58.35.101
    Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=-1--1, 24 fps, 24k tbn, 24 tbc
    Metadata:
      encoder         : Lavc58.65.103 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
    Stream #0:1: Audio: aac (LC) (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 69 kb/s
    Metadata:
      encoder         : Lavc58.65.103 aac
frame=   69 fps=0.0 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A dup=0 drop=1 speed=   0x    
frame=   97 fps=0.0 q=-1.0 Lsize=     128kB time=00:00:03.91 bitrate= 267.1kbits/s dup=0 drop=2 speed=5.04x    
video:119kB audio:6kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 2.208101%
[libx264 @ 0000020190759300] frame I:1     Avg QP:12.88  size:103994
[libx264 @ 0000020190759300] frame P:24    Avg QP:14.05  size:   224
[libx264 @ 0000020190759300] frame B:72    Avg QP:12.67  size:   160
[libx264 @ 0000020190759300] consecutive B-frames:  1.0%  0.0%  0.0% 99.0%
[libx264 @ 0000020190759300] mb I  I16..4: 61.7%  0.0% 38.3%
[libx264 @ 0000020190759300] mb P  I16..4:  0.1%  0.0%  0.0%  P16..4:  0.5%  0.1%  0.0%  0.0%  0.0%    skip:99.3%
[libx264 @ 0000020190759300] mb B  I16..4:  0.0%  0.0%  0.0%  B16..8:  1.6%  0.0%  0.0%  direct: 0.0%  skip:98.4%  L0:81.1% L1:18.9% BI: 0.0%
[libx264 @ 0000020190759300] coded y,uvDC,uvAC intra: 34.5% 17.3% 15.6% inter: 0.0% 0.1% 0.0%
[libx264 @ 0000020190759300] i16 v,h,dc,p: 70% 19%  7%  3%
[libx264 @ 0000020190759300] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 40% 22% 12%  4%  5%  5%  3%  5%  4%
[libx264 @ 0000020190759300] i8c dc,h,v,p: 80%  8% 10%  2%
[libx264 @ 0000020190759300] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 0000020190759300] ref P L0: 97.6%  0.3%  1.5%  0.6%
[libx264 @ 0000020190759300] ref B L0:  1.8% 98.2%
[libx264 @ 0000020190759300] ref B L1: 99.9%  0.1%
[libx264 @ 0000020190759300] kb/s:239.28
[aac @ 000002019075bf40] Qavg: 8004.814
======================== 


  


  I have also tried the following command line

  


  "S:\_BINS\ffmpeg-2023-03-20\bin\ffmpeg.exe" -loop 1 -i "HELLO.JPG" -i "HELLO.MP3" -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -y -shortest "HELLO_aac.mp4"    


  


  With similar long dead tail silence ???

  


• FFMPEG — using 'amix' to combine short audio clip with a video results in final video's sound cutting off early

  12 avril 2022, par kilika

  I am trying to combine the following :

  


  (a) : 29s video clip that has its own audio that lasts the entire duration

  


  (b) : audio clip I want to play at the start of the video, in conjunction with original audio, and is 2 seconds long

  


  I successfully use 'amix' to obtain a video at the end with combined audio, but the problem is that the final video's audio cuts off at around 26 out of the 29 seconds of the video and goes silent.

  


  What doesn't make any sense is that the resulting video plays as it should, with the audio successfully mixed. But the output video's audio stream loses the last 3 seconds.

  


  Here's the 'amix' command I'm using (sending via subprocess) :

  


  subprocess.call(['ffmpeg','-i', input.mp4', '-i', "audioclip.mp3", '-filter_complex', 'amix', output.mp4'])


  


  I've also used versions of this command that spell out the -map "0:a" and -map "1:a", or tried using 'amix=inputs=2:duration:longest' among many other additions. All lead to the same problem : the final combined video's audio drops out with 3 seconds remaining in the video, even though the initial 'input.mp4' video has a full 29 out of 29 seconds of audio.

  


  Does anyone know why these last several seconds of audio from [a] are missing in the final video ?

  


  _________________________________________________________________

  


  edit : Below is my output when I run the amix command listed above :

  


  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'RuneBearinstakill_advanced.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf59.20.101
  Duration: 00:00:29.77, start: 0.000000, bitrate: 5441 kb/s
  Stream #0:0[0x1](eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt470bg/bt470bg/smpte170m, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 5304 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
    Metadata:
      handler_name    : Bento4 Video Handler
      vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      handler_name    : Bento4 Sound Handler
      vendor_id       : [0][0][0][0]
[mp3 @ 000001f0c8ec2040] Estimating duration from bitrate, this may be inaccurate
Input #1, mp3, from 'TTS_clip.mp3':
  Duration: 00:00:01.90, start: 0.000000, bitrate: 32 kb/s
  Stream #1:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
Stream mapping:
  Stream #0:1 (aac) -> amix (graph 0)
  Stream #1:0 (mp3float) -> amix (graph 0)
  amix:default (graph 0) -> Stream #0:0 (aac)
  Stream #0:0 -> #0:1 (h264 (native) -> h264 (libx264))
Press [q] to stop, [?] for help
[libx264 @ 000001f0c8cbe5c0] using SAR=1/1
[libx264 @ 000001f0c8cbe5c0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 000001f0c8cbe5c0] profile High, level 4.0, 4:2:0, 8-bit
[libx264 @ 000001f0c8cbe5c0] 264 - core 164 r3094 bfc87b7 - H.264/MPEG-4 AVC codec - Copyleft 2003-2022 - 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=24 lookahead_threads=4 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, mp4, to 'RuneBearinstakill_advancedwithtts.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf59.20.101
  Stream #0:0: Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s
    Metadata:
      encoder         : Lavc59.25.100 aac
  Stream #0:1(eng): Video: h264 (avc1 / 0x31637661), yuv420p(tv, bt470bg/bt470bg/smpte170m, progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 30 fps, 15360 tbn (default)
    Metadata:
      handler_name    : Bento4 Video Handler
      vendor_id       : [0][0][0][0]
      encoder         : Lavc59.25.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
frame=  893 fps=110 q=-1.0 Lsize=   18717kB time=00:00:29.66 bitrate=5168.5kbits/s speed=3.66x    
video:18256kB audio:433kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.150179%
[aac @ 000001f0c8f9ebc0] Qavg: 921.259
[libx264 @ 000001f0c8cbe5c0] frame I:4     Avg QP:21.33  size: 71366
[libx264 @ 000001f0c8cbe5c0] frame P:633   Avg QP:23.32  size: 23837
[libx264 @ 000001f0c8cbe5c0] frame B:256   Avg QP:25.22  size: 12968
[libx264 @ 000001f0c8cbe5c0] consecutive B-frames: 57.2% 10.3% 10.1% 22.4%
[libx264 @ 000001f0c8cbe5c0] mb I  I16..4: 17.9% 71.4% 10.8%
[libx264 @ 000001f0c8cbe5c0] mb P  I16..4:  6.9% 17.6%  0.8%  P16..4: 43.1%  6.5%  1.5%  0.0%  0.0%    skip:23.6%
[libx264 @ 000001f0c8cbe5c0] mb B  I16..4:  1.5%  4.2%  0.3%  B16..8: 39.7%  4.6%  0.5%  direct: 1.6%  skip:47.6%  L0:55.9% L1:41.8% BI: 2.3%
[libx264 @ 000001f0c8cbe5c0] 8x8 transform intra:69.5% inter:87.3%
[libx264 @ 000001f0c8cbe5c0] coded y,uvDC,uvAC intra: 35.6% 26.8% 0.8% inter: 13.4% 10.8% 0.0%
[libx264 @ 000001f0c8cbe5c0] i16 v,h,dc,p: 21% 37% 12% 30%
[libx264 @ 000001f0c8cbe5c0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 25% 26% 21%  4%  5%  5%  6%  4%  5%
[libx264 @ 000001f0c8cbe5c0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 24% 28% 15%  5%  7%  7%  7%  5%  4%
[libx264 @ 000001f0c8cbe5c0] i8c dc,h,v,p: 67% 18% 14%  1%
[libx264 @ 000001f0c8cbe5c0] Weighted P-Frames: Y:0.2% UV:0.0%
[libx264 @ 000001f0c8cbe5c0] ref P L0: 72.3% 15.4%  8.7%  3.6%  0.0%
[libx264 @ 000001f0c8cbe5c0] ref B L0: 88.9%  9.5%  1.6%
[libx264 @ 000001f0c8cbe5c0] ref B L1: 97.7%  2.3%
[libx264 @ 000001f0c8cbe5c0] kb/s:5024.13


  


  And here is the output when I check the stream durations for the input video and the output video, showing how the output video's audio stream is somehow reduced by several seconds after the amix :

  


  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'RuneBearinstakill_advanced.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf59.20.101
  Duration: 00:00:29.77, start: 0.000000, bitrate: 5403 kb/s
  Stream #0:0[0x1](eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt470bg/bt470bg/smpte170m, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 5266 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
    Metadata:
      handler_name    : Bento4 Video Handler
      vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      handler_name    : Bento4 Sound Handler
      vendor_id       : [0][0][0][0]
[STREAM]
duration=29.766667
[/STREAM]
[STREAM]
duration=29.738000
[/STREAM]

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'RuneBearinstakill_advancedwithtts.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf59.20.101
  Duration: 00:00:29.77, start: 0.000000, bitrate: 5098 kb/s
  Stream #0:0[0x1](und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
      vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt470bg/bt470bg/smpte170m, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 4971 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
    Metadata:
      handler_name    : Bento4 Video Handler
      vendor_id       : [0][0][0][0]
[STREAM]
duration=27.477000
[/STREAM]
[STREAM]
duration=29.766667


  


• RoQ on Dreamcast

  18 mars 2011, par Multimedia Mike — Sega Dreamcast

  I have been working on that challenge to play back video on the Sega Dreamcast. To review, I asserted that the RoQ format would be a good fit for the Sega Dreamcast hardware. The goal was to play 640x480 video at 30 frames/second. Short version : I have determined that it is possible to decode such video in real time. However, I ran into certain data rate caveats.

  First off : Have you ever wondered if the Dreamcast can read an 80mm optical disc ? It can ! I discovered this when I only had 60 MB of RoQ samples to burn on a disc and a spindle full of these 210MB-capacity 80mm CD-Rs that I never have occasion to use.

  
  
  

  New RoQ Library
  There are open source RoQ decoders out there but I decided to write a new one. A few reasons : 1) RoQ is so simple that I didn’t think it would take too long ; 2) it would be nice to have a RoQ library that is license-compatible (BSD-like) with the rest of the KallistiOS distribution ; 3) the idroq.tar.gz distribution, while license-compatible, has enough issues that I didn’t want to correct it.

  Thankfully, I was correct about the task not being too difficult : I put together a new RoQ decoder in short order. I’m a bit embarrassed to admit that the part I had the most trouble with was properly converting YUV -> RGB.
  
  About the approach I took : While the original idroq.tar.gz decoder maintains YUV 4:2:0 codebooks (which led to chroma bugs during motion compensation) and FFmpeg’s decoder maintains YUV 4:4:4 codebooks, this decoder is built to convert the YUV 4:2:0 vectors into RGB565 vectors during the vector unpacking phase. Thus, the entire frame is rendered in RGB565 — no lengthy YUV -> RGB conversion after decoding — and all pixels are shuffled around as 16-bit units (minor speedup vs. shuffling everything as bytes).

  I also entertained the idea of maintaining YUYV codebooks (since the DC supports that colorspace as a texture format). But I scrapped that idea when I remembered it would lead to the same chroma bleeding problem seen in the original idroq.tar.gz decoder.

  Onto The Dreamcast
  I developed the library on a Linux computer, allowing it to output a series of PNM files for visual verification and debugging. Dropping it into a basic DC/KOS-compatible program was trivial and the first order of business was profiling.

  At first, I profiled the entire decode operation : open file, then read and decode each chunk while tossing away the results. I was roundly disappointed to see that, e.g., an 8.5-second RoQ sample needed a little more than 20 seconds to complete. Not real time. I performed a series of optimizations on the decoding library that netted notable performance gains when profiling on Linux. When I brought these same optimizations over to the DC, decoding time didn’t improve at all. This was my first suspicion that perhaps my assumptions regarding the DC’s optical drive’s data rate were not correct.

  Dreamcast Data Rate Profiling
  Let’s start with some definitions : In terms of data rate, an ’X’, i.e., 1X is the minimum data rate needed to read CD quality audio from a disc. At that speed, a drive should be able to stream 75 sectors each second. When reading mode 1/form 1 CD-ROM data, each sector has 2048 bytes (2 kbytes), so a single-speed data rate should achieve 150 kbytes/sec.

  The Dreamcast is supposed to possess a 12X optical drive. This would imply a maximum data rate of 150 kbytes/sec * 12 = 1800 kbytes/sec.

  Rigging up a trivial experiment using the RoQ samples burned on a few different CD-R discs, the best data rate I can see is about 500-525 kbytes/sec, or around 3.5X.

  Where’s the discrepancy ? My first theory has to do with the fact that not all optical media is created equal. This is why optical drives often advertise a slew of numbers which refer to the best theoretical speed for reading a CD vs. writing a CD-R vs. writing a CD-RW, etc. Perhaps the DC drive can’t read CD-Rs very quickly. To test this theory, I tried streaming a large file from a conventionally mastered CD-ROM. This worked well for the closest CD-ROM I had on hand : I was able to stream data at a rate that works out to about 6.5X.

  I smell a science project for another evening : Profiling read speeds from a mastered CD-ROM, burned CD-R, and also a mastered GD-ROM, on each of the 3 Dreamcast consoles I possess (I’ve heard that there’s variance between optical drives depending on manufacturing run).

  The Good News
  I added a little finer-grained code to profile just the video decoding functions. The good news is that the decoder meets my real time goals : That 8.5-second RoQ sample encoded at 640x480x30fps makes its way through the video decoding functions on the DC in a little less than 5 seconds. If the optical drive can supply the data fast enough, the video decoder can take care of the rest.

  The RoQ encoder included with FFmpeg does not honor any bitrate parameters. Instead, I encoded the same file at 320x240. It reportedly decoded in real time and can be streamed in real time as well.

  I say "reportedly" because I’m simply working from textual output at this point ; the next phase is to hook the decoder up to the display hardware.