Stack Overflow
Stack Overflow

Questions tagged [codec]

Codec is an implementation of compression and decompression of digital data streams and signals in different scales. Digital data like audio, video and electronic documents are been compressed and decompressed using codecs.

A codec can consist of two components: an encoder and a decoder. The encoder performs the compression (encoding) function and the decoder performs the decompression (decoding) function. Some codecs include both of these components and some codecs only include one of them.

There is mainly two kind of data compression technique.

  1. Lossless
  2. Lossy

Lossless Data Compression
Lossless data compression allows the exact original data to be reconstructed from the compressed data.

Lossy Data Compression
Lossy compression is a data encoding method that compresses data by discarding (losing) some of it. The procedure aims to minimize the amount of data that need to be held, handled.

List of Different Codecs
Wikipedia Codec List According to Catagory

FAQs
FAQ about Codecs by Microsoft
Codec Guide FAQ

Other Useful Links
Microsoft codec programming guide
ffmpeg codec programming
Codecguide

1364 questions
104
votes
7 answers

Difference between open and codecs.open in Python

There are two ways to open a text file in Python: f = open(filename) And import codecs f = codecs.open(filename, encoding="utf-8") When is codecs.open preferable to open?
BlogueroConnor
  • 1,673
  • 4
  • 16
  • 18
56
votes
1 answer

What is video timescale, timebase, or timestamp in ffmpeg?

There does not seem to be any explanation online as to what these are. People talk about them a lot. I just want to know what they are and why they are significant. Using -video_track_timescale, how would I determine a number for it? Is it random?…
Please Help
  • 659
  • 1
  • 7
  • 11
49
votes
6 answers

ffmpeg convert mov file to mp4 for HTML5 video tag IE9

I looked everywhere here and on google - there is no valid command that works for IE9. some how IE9 is missing something. All that I tried worked everywhere else: chrome,safari,mobile device etc... I want one command that will convert it and I can…
Adidi
  • 4,821
  • 3
  • 19
  • 28
44
votes
5 answers

Turn image sequence into video with transparency

I've got what seems like it should be a really simple problem, but it's proving much harder than I expected. Here's the issue: I've got a fairly large image sequence consisting of numbered frames (output from Maya, for what its worth). The images…
Cody Hatch
  • 8,527
  • 6
  • 27
  • 36
37
votes
3 answers

Choosing a video codec for screen recording

I'm doing a series of tutorials by recording the screen and my voice. Just as PNG works best for screenshots, while JPEG is better suited for photographs (although lossy), which video encoding & container formats are better for screen…
Dheeraj Vepakomma
  • 18,747
  • 12
  • 67
  • 98
29
votes
6 answers

VLC: How to convert from mp4 to webm

How can I convert from mp4 to webm using VLC, if possible? What codec should I choose? Do I need to recode the sound? I'm trying to put html5 video on a website with flash as fallback. As I understand it, it's the only format (webm) that Firefox…
OZZIE
  • 3,932
  • 3
  • 39
  • 51
27
votes
13 answers

Flutter images not loaded (EXCEPTION: resolving an image codec)

When I try to run images assets doesn't get properly loaded, I am getting an exception: The following assertion was thrown resolving an image codec: Unable to load asset: /images/p8.png` Some weeks ago it was working and now it stopped. I tried…
Andrea Zanini
  • 382
  • 1
  • 3
  • 8
24
votes
4 answers

Where to start learning about audio or video codecs?

I am very much confused to know what happens inside the codecs. I want to learn about the elements inside audio encoders and decoders. Would be very happy if you can provide me some links where i can find some good study material. Precisely I would…
Vamsi
  • 5,123
  • 6
  • 27
  • 32
22
votes
3 answers

What do double parentheses mean in a function call? e.g. func(stuff)(stuff)?

Original title: "Help me understand this weird Python idiom? sys.stdout = codecs.getwriter('utf-8')(sys.stdout)" I use this idiom all the time to print a bunch of content to standard out in utf-8 in Python 2.*: sys.stdout =…
user18015
22
votes
1 answer

How to use Blob URL, MediaSource or other methods to play concatenated Blobs of media fragments?

Am attempting to implement, for lack of a different description, an offline media context. The concept is to create 1 second Blobs of recorded media, with the ability to Play the 1 second Blobs independently at an HTMLMediaElement Play the full…
guest271314
  • 1
  • 10
  • 82
  • 156
21
votes
5 answers

what is the codec for mp4 videos in python OpenCV

fourcc = cv2.cv.CV_FOURCC(*'XVID') The above line is used for avi video. In the same fashion, which codec do we use for mp4 videos in Ubuntu?
Suhail Ahmed Khan
  • 405
  • 2
  • 5
  • 10
21
votes
2 answers

Decoding Opus audio data

I am trying to decode an Opus file back to raw 48 kHz. However I am unable to find any sample code to do that. My current code is this: void COpusCodec::Decode(unsigned char* encoded, short* decoded, unsigned int len) { int…
tmighty
  • 8,222
  • 19
  • 78
  • 182
20
votes
2 answers

Enabling libfdk_aac in ffmpeg installed with Homebrew

On macOs I always used to install or update ffmpeg through Homebrew. I use the libfdk_aac audio codec a lot so I always did this: brew reinstall ffmpeg --with-fdk-aac For some reason, since one or two brew updates, ffmpeg can no longer be installed…
RocketNuts
  • 7,383
  • 6
  • 29
  • 64
18
votes
2 answers

Concept about Multimedia Codecs (Container,Format, Codec,Muxer,Demuxer)

I have gone thorugh lot of multimedia stuff last week and now messed up in few questions.These are related to my work on Developing a Media Player.My questions below are based on that only. I am also looking out for ebook/resource on Multimedia…
Raulp
  • 6,261
  • 11
  • 73
  • 129
18
votes
3 answers

Is there a good open codec for screencast compression

Video captured from computer screens can be compressed very well by codecs that are optimised for screen video. Generally, this means taking into account that large areas of the screen don't change between frames, and that when areas change they are…
Bernie Sumption
  • 380
  • 4
  • 11
1
2 3
…
90 91