codec - Observing the sequence of I, P and B frames

I am using an X264 encoder. How can I possibly see the sequence of I, P, B frames how they are being encoded while encoding I mentioned these parameterslikely x264 --crf 23 --tune fastdecode --fps 64 --keyint 1 --min-keyint 1 --no-scenecut --input-res 4096*2048 --bframes 3 -o filenameIs it possible to see these sequences while decoding (using ijkplayer)?...Read more

codec - How do I add support for a proprietary image format in Windows Photo Viewer / Picasa Viewer

I am working on developing a lossless compression algorithm using MATLAB.I would like to see some of my compressed images on windows photo viewer. Could anyone direct me on how to go about doing this? Where may I find specifications to create a codec that would work with windows photo viewer?I am guessing that I could create a codec as a .ddl file and place it in some windows directory and Photo Viewer could decode my file format. I have seen some softwares from Nikon imaging that, once installed, allowed photo viewer to display the .NEF (Nikon...Read more

pjsip - Changing default (outgoing) codec to OPUS in Freeswitch

I am new to Freeswitch.I want to change the default codec to OPUS. I made changes to vars.xml,dingaling.xml as per I have loaded the mod_opus module as well.But still I am receving the RTP in PCMA/PCMU following the link . When I do eval $${global_codec_prefs} I get OPUS,PCMA,PCMU,VP8. Please let me know what am I missing.Also, I am using PJSIP as one of the SIP clients. Do I need to make any changes in PJSIP too?...Read more

codec - AviSynth can't open my AVI file: “AVISource: Couldn't locate a decompressor for fourcc dvds”

I simply want to open an AVI file with AviSynth and feed it into VirtualDub. However, when I open my .avs script (consisting of just one AviSource() call), I get the following error: Avisynth open failure: AVISource: Couldn't locate a decompressor for fourcc dvds (H:\Videos\QTGMC\test.avs, line 1)The required dvsd codec seems to be installed, according to software called GSpot (which identifies a video file's required codec's). Does anyone know why I can't open this file and how to fix it?...Read more

codec - AVI subtype playback issues

I have two AVI videos. one will play in an application i am using and the other will not.looking at them in Media Player Classic properties, they have exactly the same specificationsCodec : DVSD Named: DVC/DVbut looking at them in GSpot, I finally found a difference.the working file uses OpenDML AVI 2.0whereas the file that will not open uses AVI 1.0I need to convert one to the other, but i cant find a way to convert from one codec to a different version of the same codec, muchless how to find different editions of the same codec.If anyone has ...Read more

codec - NVENC SDK examples

I am trying to run the NVENC encoder SDK examples which are able to provide hardware accelerated video encoding.I am trying to run the nvencoder sample with the dataset I found here: ran it with the following command line:NvEncoder.exe -i tulips_yuv420_inter_planar_qcif.yuv -o test.mp4 -size 176 144The resulting file that is produced cannot really be played by any media player. VLC sort of loads it but does not produce any image that I was expecting.L...Read more

codec - What are the limitations of each VC1 profile?

When I'm trying to a conversion with the following parameters:mediaItem.OutputFormat.VideoProfile = new MainVC1VideoProfile() { Size = new System.Drawing.Size(1920, 1200), Bitrate = new VariableQualityBitrate(75), Complexity = VideoComplexity.Normal, FrameRate = 1, KeyFrameDistance = TimeSpan.FromSeconds(20) };I'm getting the following error: The combined width, height and frame rate are too...Read more

compression - Which codec is best and what should be their parameters value?

I'm a beginner in the field of audio codec and finding it hard to understand; how does sampling rate, bit rate and any other parameter affect the encoding/decoding[Audio format], the quality of audio and file size. I read constant bit rate is good than variable bit rate, but how to know what amount of bit rate would be perfect to encode the file in as small size as possible without compromising the quality. I'm specifically focusing on audio codec for present.I had heard about the OPUS, SILK, G.722, SPEEX, but don't know which one should I use ...Read more

codec - image -> video -> image not lossless using avconv

I'm trying to test the amount of information lost with some different video codecs. I've got a python script which uses PyPNG to write a series of 8 bit RGB images. I then encode it using avconv, for instanceavconv -r 1 -i ../frames/data%03d.png -c:v ffv1 -qscale:v 0 -r 1 outffv1.aviI then decode this back into pngs like soavconv -r 1 -i outffv1.avi -r 1 ./outffv1/frame%03d.pngBut when I compare the images before and after the video compression, they are different (mean absolute error of ~~15%). The thing that is confusing me is that this is tr...Read more

codec - how opus adapts to variable bandwidth?

How does opus reacts dynamically if bandwidth in network is decreased or increased?I am researching on it but could not find the right answer. I came to know that it supports variable bit-rate, but how does it handles changing bit-rate according to bandwidth dynamically?...Read more

codec - Can DICOM pixel data compression decompression mess with window center and window width

I am viewing Computerized Tomography ( CT) DICOM images. These were originally uncompressed DICOM images. I have lossless J2K compressed form of these DICOM images: Transfer syntax = 1.2.840.10008. (JPEG-2K Lossless). When I uncompress these DICOM images back: Transfer Syntax =1.2.840.10008.1.2.1 (Little Endian Explicit) and view both the compressed and uncompressed DICOM images side by side in a DICOM viewer then I observe that - The compressed and uncompressed images need a different "window level " for viewing ( "Window level" =...Read more

codec - Why is x264 / x265 lossless encoding slower than lossy encoding

I am comparing x264 and x265 encoders, with lossless and medium presets.I am so surprised to see below performance results.| Format | Size (KB) | fps ||********************|*************|******|| YUV 420 | 9,182,363 | || | | || x265 (--lossless) | 442,890 | 1.8 || x265 (--medium) | 12,243 | 2.8 || | | || x264 (--lossless) | 319,139 | 7.2 | | x264 (--medium) | 25,747 | 7.5 | It raises two questions to meWhy lossl...Read more

codec - Convert a DCR video file

I have a DCR (file has a .dcr extension) video file coming from a video surveillance device ( I don't know the make and model of the recorder )I'm unable to read it with VLC, Media Player, and it won't open in Virtual Dub or can't be converted with the standard "ffmpeg.exe video.dcr output.avi" command line.But I'm able to get a very basic** playback of the video stream with MPC-HC player of the Combined Community Codec Pack. Unfortunately, the audio stream (which I'm looking for) will not play. According to the MPC-HC player file info, I'm dea...Read more