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• Revision 6ce718eb18 : Merge "End of orientation zero group experiment" into experimental

  22 avril 2013, par Deb Mukherjee

  Changed Paths : Modify /vp9/decoder/vp9_decodframe.c Modify /vp9/encoder/vp9_encodemb.c Modify /vp9/encoder/vp9_rdopt.c Merge "End of orientation zero group experiment" into experimental

• Studying A Game Wave Disc

  23 novembre 2010, par Multimedia Mike — Game Hacking

  I picked up a used copy of game called Gemz — a rather flagrant Bejeweled clone — for a game console called Game Wave Family Entertainment System. Heard of it ? Neither had I. But the game media is optical, so I had to get it and study it.

  
  
  

  When mounted in Linux (as UDF), the disc is reported to contain 2.8 GB of data, so it has to be a DVD. 810 MB of that is dedicated to the movies/ directory. Multimedia format ? Just plain, boring MPEG files (very YouTube-friendly— here’s the opening animation). Deeper digging reveals some more subdirectories called movies/ that, combined, occupy the lion’s share of the disc space. Additionally, there are several single-frame .m2v files in a directory called iframes/ which are used to encode things like load screens.

  
  
  

  There are more interesting data files including .zbm files for images and fonts, and .zwf files for audio. I suspect that these stand for zipped bitmap and zipped wave file, respectively. They can’t be directly unzipped with ’gunzip’. Some of the numbers at the start of some files lead me to believe they can be easily decompressed with standard zlib facilities.

  Based on the binary files on the Gemz disc, I couldn’t find any data on what CPU this system might use. A little Googling led me to this page at the Video Game Console Library which pegs the brain as a Mediamatics 6811. Some searching for that leads me to a long-discontinued line of hardware from National Semiconductor.

  The Console Library page also mentions that the games were developed using the Lua programming language. Indeed, there are many Lua-related strings in the game’s binaries (’zlib’ also makes an appearance).

• Why is there an audio delay on recording video stream with ffmpeg ?

  25 décembre 2023, par mqwerty

  I am trying to record video and audio stream (Line in Microphone Analog Audio) which are streaming from broadcaster computer with those parameters in the recorder computer ;

  


  ffmpeg record parameters :

  


  /usr/bin/ffmpeg -y -buffer_size max -thread_queue_size 8192 -i udp://225.0.5.11:1026 -buffer_size max -thread_queue_size 8192 -i udp://225.0.5.11:1032 -map 0:v -map 1:a -metadata title=COMPUTER-01_metadata_file -metadata creation_time="2023-12-25 13:25:29" -threads 0 -c:v copy -c:a copy -movflags +faststart -f segment -segment_time 01:00:00 -segment_atclocktime 1 -reset_timestamps 1 -strftime 1 -segment_format mp4 -t 120 test_record_video_with_audio_%Y-%m-%d_%H-%M-%S.mp4


  


  The ffmpeg started and finished successfully, but when I open the recorded video with mpv like (mpv test_record_video_with_audio.mp4), I realized that there is a 5-6 seconds delay in audio. How can I prevent the delay of audio in the recorded mp4 file without using offset ? My last option is setting offset but I think that it is not safe according to any changes in network or etc.

  


  FFMPEG version on both computer :

  


  ffmpeg version 4.2.9 Copyright (c) 2000-2023 the FFmpeg developers
built with gcc 8 (GCC)


  


  BROADCASTER COMPUTER :

  


  sysctl.conf :

  


  No added configurations.


  


  ethtool output :

  


  Supported ports: [ TP ]
Supported link modes:   100baseT/Full
                        1000baseT/Full
                        10000baseT/Full
                        2500baseT/Full
                        5000baseT/Full
Supported pause frame use: Symmetric
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes:  100baseT/Full
                        1000baseT/Full
                        10000baseT/Full
Advertised pause frame use: Symmetric
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Speed: 10000Mb/s
Duplex: Full
Auto-negotiation: on
Port: Twisted Pair
PHYAD: 0
Transceiver: internal
MDI-X: Unknown
Supports Wake-on: d
Wake-on: d
    Current message level: 0x00000007 (7)
                           drv probe link
Link detected: yes


  


  ffmpeg video stream :

  


  ffmpeg -fflags +genpts -f x11grab -framerate 30 -video_size uhd2160 -i :0 -c:v hevc_nvenc -preset fast -pix_fmt bgr0 -b:v 3M -g 25 -an -f mpegts udp://225.0.5.11:1026


  


  ffmpeg audio stream :

  


  ffmpeg -f alsa -i hw:0,0 -c:a aac -ar 48000 -b:a 1024K -ab 512k -f rtp_mpegts rtp://225.0.5.11:1032


  


  nvidia-smi :

  


  | NVIDIA-SMI 535.129.03             Driver Version: 535.129.03   CUDA Version: 12.2     |
|-----------------------------------------+----------------------+----------------------+
| GPU  Name                 Persistence-M | Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp   Perf          Pwr:Usage/Cap |         Memory-Usage | GPU-Util  Compute M. |
|                                         |                      |               MIG M. |
|=========================================+======================+======================|
|   0  NVIDIA T400 4GB                Off | 00000000:5B:00.0 Off |                  N/A |
| 38%   38C    P8              N/A /  31W |    207MiB /  4096MiB |      0%      Default |
|                                         |                      |                  N/A |
+-----------------------------------------+----------------------+----------------------+
|   1  NVIDIA RTX A4000               Off | 00000000:9E:00.0 Off |                  Off |
| 41%   59C    P2              41W / 140W |    766MiB / 16376MiB |     17%      Default |
|                                         |                      |                  N/A |
+-----------------------------------------+----------------------+----------------------+
                                                                                         
+---------------------------------------------------------------------------------------+
| Processes:                                                                            |
|  GPU   GI   CI        PID   Type   Process name                            GPU Memory |
|        ID   ID                                                             Usage      |
|=======================================================================================|
|    0   N/A  N/A      3227      G   /usr/libexec/Xorg                           114MiB |
|    0   N/A  N/A      3423      G   /usr/bin/gnome-shell                         87MiB |
|    1   N/A  N/A      3227      G   /usr/libexec/Xorg                           285MiB |
|    1   N/A  N/A      3423      G   /usr/bin/gnome-shell                         91MiB |
|    1   N/A  N/A      3762      C   ffmpeg                                      372MiB |
+---------------------------------------------------------------------------------------+


  


  lscpu output :

  


  

Architecture:        x86_64
CPU op-mode(s):      32-bit, 64-bit
Byte Order:          Little Endian
CPU(s):              96
On-line CPU(s) list: 0-95
Thread(s) per core:  2
Core(s) per socket:  24
Socket(s):           2
NUMA node(s):        2
Vendor ID:           GenuineIntel
BIOS Vendor ID:      Intel(R) Corporation
CPU family:          6
Model:               85
Model name:          Intel(R) Xeon(R) Gold 5220R CPU @ 2.20GHz
BIOS Model name:     Intel(R) Xeon(R) Gold 5220R CPU @ 2.20GHz
Stepping:            7
CPU MHz:             2200.000
CPU max MHz:         4000.0000
CPU min MHz:         1000.0000
BogoMIPS:            4400.00
Virtualization:      VT-x
L1d cache:           32K
L1i cache:           32K
L2 cache:            1024K
L3 cache:            36608K
NUMA node0 CPU(s):   0-23,48-71
NUMA node1 CPU(s):   24-47,72-95


  


  OS : CentOS Stream release 8


  


  RECORDER COMPUTER :

  


  sysctl.conf :

  


  net.core.rmem_max=16777216
net.core.wmem_max=16777216
net.ipv4.tcp_rmem= 4096 87380 16777216
net.ipv4.tcp_wmem= 4096 65536 16777216
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_timestamps = 1
net.ipv4.tcp_sack = 1
net.ipv4.tcp_no_metrics_save = 0
net.core.netdev_max_backlog = 50000
net.core.optmem_max=25165824


  


  lscpu output :

  


  Architecture:        x86_64
CPU op-mode(s):      32-bit, 64-bit
Byte Order:          Little Endian
CPU(s):              96
On-line CPU(s) list: 0-95
Thread(s) per core:  2
Core(s) per socket:  24
Socket(s):           2
NUMA node(s):        2
Vendor ID:           GenuineIntel
BIOS Vendor ID:      Intel
CPU family:          6
Model:               106
Model name:          Intel(R) Xeon(R) Gold 5318Y CPU @ 2.10GHz
BIOS Model name:     Intel(R) Xeon(R) Gold 5318Y CPU @ 2.10GHz
Stepping:            6
CPU MHz:             3400.000
CPU max MHz:         3400.0000
CPU min MHz:         800.0000
BogoMIPS:            4200.00
Virtualization:      VT-x
L1d cache:           48K
L1i cache:           32K
L2 cache:            1280K
L3 cache:            36864K


  


  ethtool output :

  


  Supported ports: [ TP ]
    Supported link modes:   1000baseT/Full
                            10000baseT/Full
    Supported pause frame use: Symmetric Receive-only
    Supports auto-negotiation: Yes
    Supported FEC modes: Not reported
    Advertised link modes:  1000baseT/Full
                            10000baseT/Full
    Advertised pause frame use: Symmetric
    Advertised auto-negotiation: Yes
    Advertised FEC modes: Not reported
    Speed: 10000Mb/s
    Duplex: Full
    Auto-negotiation: on
    Port: Twisted Pair
    PHYAD: 12
    Transceiver: internal
    MDI-X: Unknown
    Supports Wake-on: d
    Wake-on: d
        Current message level: 0x00002081 (8321)
                               drv tx_err hw
    Link detected: yes


  


  No NVIDIA Graphic Driver

  


  OS : CentOS Stream release 8


  


  I tried audio encoding while recording like :

  


  "-c:a", "aac",  
"-ar", "48000", 
"-b:a", "128k",


  


  I also tried :

  


  "aresample=async=1"



  


  Unfortunately,these did not have any improvements on preventing latency in audio.