Recherche avancée

Sur d’autres sites (6442)

• Convert 2 channel mp4 to each mono wav file using FFMPEG or Python code

  30 mai 2024, par Harish Alwala

  I am new to audio files and its codecs.

  


  I would like to convert a 2 channel mp4 file to a single mono wav files.

  


  My understanding is a when I say 2 channel, it stores speech coming from each microphone in a separate channel. And when I split the channels to each individual mono wav files, I get speech of each microphone.

  


  My intension here is to get the speech from each channel and convert them to text. This way I can set the name of the speaker based on channel.

  


  I tried with ffmpeg and python code as well, unfortunately I get two files with same content.

  


  Looking at the following details
can someone construct ffmpeg command or python script to convert the 2 channel mp4 file to 2 individual mono wav files.

  


  FFprobe
ffprobe -i Two-Channel.mp4 -show_streams -select_streams a

  


  Result

  


  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: isommp42
    encoder         : Google
  Duration: 00:52:42.19, start: 0.000000, bitrate: 421 kb/s
  Stream #0:0[0x1](und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709, progressive), 640x360 [SAR 1:1 DAR 16:9], 322 kb/s, 25 fps, 25 tbr, 12800 tbn (default)
      Metadata:
        handler_name    : ISO Media file produced by Google Inc.
        vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 96 kb/s (default)
      Metadata:
        handler_name    : ISO Media file produced by Google Inc.
        vendor_id       : [0][0][0][0]
[STREAM]
index=1
codec_name=aac
codec_long_name=AAC (Advanced Audio Coding)
profile=LC
codec_type=audio
codec_tag_string=mp4a
codec_tag=0x6134706d
sample_fmt=fltp
sample_rate=44100
channels=2
channel_layout=stereo
bits_per_sample=0
initial_padding=0
id=0x2
r_frame_rate=0/0
avg_frame_rate=0/0
time_base=1/44100
start_pts=0
start_time=0.000000
duration_ts=139452416
duration=3162.186304
bit_rate=96000
max_bit_rate=N/A
bits_per_raw_sample=N/A
nb_frames=136184
nb_read_frames=N/A
nb_read_packets=N/A
extradata_size=16
DISPOSITION:default=1
DISPOSITION:dub=0
DISPOSITION:original=0
DISPOSITION:comment=0
DISPOSITION:lyrics=0
DISPOSITION:karaoke=0
DISPOSITION:forced=0
DISPOSITION:hearing_impaired=0
DISPOSITION:visual_impaired=0
DISPOSITION:clean_effects=0
DISPOSITION:attached_pic=0
DISPOSITION:timed_thumbnails=0
DISPOSITION:non_diegetic=0
DISPOSITION:captions=0
DISPOSITION:descriptions=0
DISPOSITION:metadata=0
DISPOSITION:dependent=0
DISPOSITION:still_image=0
TAG:language=eng
TAG:handler_name=ISO Media file produced by Google Inc.
TAG:vendor_id=[0][0][0][0]
[/STREAM] 


  


  FFmpeg command

  


  ffmpeg -i Two-Channel.mp4 -filter_complex "pan=mono|c0=0c0" left_channel.wav

  


  python code
using FFPMEG I converted mp4 to wav and then tried below code



  


• lavf/lrc : fix comments in headers

  6 avril 2024, par Stefano Sabatini

  lavf/lrc : fix comments in headers
  

  • [DH] libavformat/lrc.c
  • [DH] libavformat/lrcdec.c
  • [DH] libavformat/lrcenc.c

• aarch64 : hevc : Produce plain neon versions of qpel_hv

  22 mars 2024, par Martin Storsjö

  aarch64 : hevc : Produce plain neon versions of qpel_hv
  As the plain neon qpel_h functions process two rows at a time,
  
  we need to allocate storage for h+8 rows instead of h+7.
  By allocating storage for h+8 rows, incrementing the stack
  
  pointer won't end up at the right spot in the end. Store the
  
  intended final stack pointer value in a register x14 which we
  
  store on the stack.
  AWS Graviton 3 :
  
  put_hevc_qpel_hv4_8_c : 386.0
  
  put_hevc_qpel_hv4_8_neon : 125.7
  
  put_hevc_qpel_hv4_8_i8mm : 83.2
  
  put_hevc_qpel_hv6_8_c : 749.0
  
  put_hevc_qpel_hv6_8_neon : 207.0
  
  put_hevc_qpel_hv6_8_i8mm : 166.0
  
  put_hevc_qpel_hv8_8_c : 1305.2
  
  put_hevc_qpel_hv8_8_neon : 216.5
  
  put_hevc_qpel_hv8_8_i8mm : 213.0
  
  put_hevc_qpel_hv12_8_c : 2570.5
  
  put_hevc_qpel_hv12_8_neon : 480.0
  
  put_hevc_qpel_hv12_8_i8mm : 398.2
  
  put_hevc_qpel_hv16_8_c : 4158.7
  
  put_hevc_qpel_hv16_8_neon : 659.7
  
  put_hevc_qpel_hv16_8_i8mm : 593.5
  
  put_hevc_qpel_hv24_8_c : 8626.7
  
  put_hevc_qpel_hv24_8_neon : 1653.5
  
  put_hevc_qpel_hv24_8_i8mm : 1398.7
  
  put_hevc_qpel_hv32_8_c : 14646.0
  
  put_hevc_qpel_hv32_8_neon : 2566.2
  
  put_hevc_qpel_hv32_8_i8mm : 2287.5
  
  put_hevc_qpel_hv48_8_c : 31072.5
  
  put_hevc_qpel_hv48_8_neon : 6228.5
  
  put_hevc_qpel_hv48_8_i8mm : 5291.0
  
  put_hevc_qpel_hv64_8_c : 53847.2
  
  put_hevc_qpel_hv64_8_neon : 9856.7
  
  put_hevc_qpel_hv64_8_i8mm : 8831.0
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DH] libavcodec/aarch64/hevcdsp_init_aarch64.c
  • [DH] libavcodec/aarch64/hevcdsp_qpel_neon.S