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Questions tagged [pcm]

PCM (Pulse-code modulation) is a method used to represent digital samples of the analog signals.

26 questions
8
votes
2 answers

Why Is Conversion From An MP3 To WAV (PCM) Lossless?

I understand that when converting between audio formats where no stream encoding is involved like when converting between WAV (PCM), AIFF, FLAC, ALAC, WMA Lossless, and etc, the process is usually lossless, because the PCM audio stream is just being…
Robin Hood
  • 3,501
6
votes
3 answers

How to play a PCM file on an UNIX system?

I'm trying to figure out how to use libmad with C. The trouble is, libmad converts audio files to .pcm files and I'm unable to find a way to play these files. There is no straightforward .pcm player, and Audacity crashes every time I try to open the…
Cookie Monster
  • 783
3
votes
2 answers

Converting WAV to PCM

I have WAV files and need to convert them to PCM (44,1k, 16bit, Mono) format. How can I do this from the DOS console?
Marco
3
votes
1 answer

FFmpeg raw audio and H264 in RTSP

Trying to grab correctly video and audio data from an IP camera Hikvision. Everything works like a charm when doing so for H264 + MP2 for example. When trying to grab RAW audio in PCM s16le - smile goes off of my face. Here is how I grab my camera…
Max Ridman
  • 33
2
votes
1 answer

How to stream desktop through audio jack (3.5) using dsp

Is it possible to stream my desktop over audio system? I mean some kind of cat /dev/fb0 > /dev/dsp? Or to pulse-code my desktop using built-in soundcard and to stream it over optical spdif audio-out port, where on the other end its raw data could…
illreality
  • 139
2
votes
2 answers

How to convert PCM to MP3?

I have some .pcm files and I want to convert them to high quality .mp3 format. How can I do that? I've tried searching online but haven't found any programs that can do this. Ay suggestions? Freeware is preferred, and I need to convert large files…
avirk
  • 15,877
2
votes
2 answers

The audio of an FFmpeg converted mov file works in VLC but fails in Adobe Premiere cs5

I use this line to convert the mov file (Mark II 5D footage) to 720p: ffmpeg -i source.mov -s 1280x728 -vf crop=1280:720:0:0 -sameq -acodec copy dest_file.mov When I drag the result file to premiere, I can only hear the first 17 frames of audio.…
ubershmekel
  • 283
2
votes
0 answers

ffmpeg - How to prevent innacurate duration when converting from pcm to wav?

I have the following command: ffmpeg -f f32le -ar 44100 -channels 2 -i input.pcm -y -acodec pcm_s16le -f wav output.wav input.pcm is the pcm data that comes from a 2 seconds wav file. However, when encoding with ffmpeg, I get the following…
Maxime Dupré
  • 79
2
votes
1 answer

How to encode into WAV ADPCM?

How to encode WAV PCM into WAV with ADPCM encoding? I tried FFmpeg. I can see from the old FFmpeg codec list, that it previously supported encoding into adpcm_adx, adpcm_ima_qt, adpcm_ima_wav, adpcm_ms, adpcm_swf and adpcm_yamaha. However, these…
Andriy Makukha
  • 383
2
votes
1 answer

How to convert raw PCM data to a valid WAV file with ffmpeg?

I run this command: ffmpeg -f f32le -i pipe:0 -f wav pipe:1 ffmpeg version 4.1-tessus https://evermeet.cx/ffmpeg/ Copyright (c) 2000-2018 the FFmpeg developers built with Apple LLVM version 10.0.0 (clang-1000.11.45.5) configuration:…
Maxime Dupré
  • 79
1
vote
2 answers

HDMI video stream

I am trying to determine the format of the audio portion of a video being sent from a digital device (DVD player, DVR, etc.) to a digital TV via an HDMI cable. My understanding is that the audio portion of this video is converted to a standard…
Bcorngtr
  • 11
1
vote
0 answers

PCM Audio file and volume

I'm working with raw pcm files(with no headers) and I was wondering, does anyone know the calculation to find the current volume of a section of sound? I have all the information on the file, such as the sample rate, channels, bits per sample, etc.…
Kelly Elton
  • 290
1
vote
1 answer

PCM sound level resets in Ubuntu 8.04

I am using Ubuntu 8.04 and seeing that PCM volume above 75% results in very poor sound quality. So, I brought it down. But the problem is, after every reboot it resets to 100%. How can I save the PCM sound level such that it does not resets on…
peakit
  • 219
1
vote
0 answers

Decoding aac to PCM in ffmpeg introduces noise in the raw PCM audio

I have a .mp4 file generated with ffmpeg as follows. ffmpeg -y -i video_extended.mp4 -itsoffset 00:00:04.00 -i output5-1.wav -map 0:0 -map 1:0 -c:v copy -c:a aac -ac 6 -ar 48000 -b:a 128k -async 1 mixed.mp4 Playing mixed.mp4 file with ffplay is…
userDtrm
  • 111
1
vote
1 answer

Extracting audio, don't understand PCM options

I've got the audio bitdepth, frequency and channels down. Pretty simple to understand, but cannot find enough information on the different PCM formats. I do understand the numbers correlate to the audio bitdepth. The reason this matters is due to…
Sea Maiden
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