I am now trying to write a music player using Gstreamer.I know that mp3 files are made up with frames (data frame and tag frame).what i want to do is extract the data frame and calculate its hash to identify a file. what should i do?
thinks in advince!
this all is done by gstremer mad element. So if you are writing application then use this element.
NOTE: mad element is comes inside gst-plugin-bad package which you can download from gstremer site
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I have several .ts files, generated by ffmpeg from live stream. All of them have the same length (well, approximately). Ideally, they are being generated constantly, with names representing the datetime when they have been recorded (for example, "2019-04-11_10-51-40.ts"). But it may happen so, that for any technical reasons recording was being stopped for a while and files have not been generated.
Now, I have a task to create a playlist of these files for a certain datetime range - and if there are no files for part of this range, I need to show just a black screen. I have a black video for this purpose with the same length as other files. So, I'm trying to manually create an .m3u8 file and insert this black video in all gaps between normal videos that I have. For example:
#EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:34
#EXT-X-PLAYLIST-TYPE:VOD
#EXTINF:30.07,
http://example.com/black_video.ts
#EXTINF:30.07,
http://example.com/black_video.ts
#EXTINF:33.33,
http://example.com/2019-04-11_10-51-40.ts
#EXTINF:33.33,
http://example.com/2019-04-11_10-52-15.ts
#EXTINF:25.00,
http://example.com/2019-04-11_10-52-48.ts
#EXT-X-ENDLIST
The problem is that when I'm trying to play this playlist, it does not play correctly: depending on player either only one black part is being played no matter how much of them there are in a sequence (VLC), or player is getting stuck after first black video ("Play HLS M3u8" extension for Chrome or player on our own service, based on hls.js).
I also tried to use #EXT-X-DISCONTINUITY; in this case all videos are being played, but progress bar drops to the very beginning after each #EXT-X-DISCONTINUITY appearance, which is also an undesired behaviour. Example:
#EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:34
#EXT-X-PLAYLIST-TYPE:VOD
#EXTINF:30.07,
http://example.com/black_video.ts
#EXT-X-DISCONTINUITY
#EXTINF:30.07,
http://example.com/black_video.ts
#EXTINF:33.33,
http://example.com/2019-04-11_10-51-40.ts
#EXTINF:33.33,
http://example.com/2019-04-11_10-52-15.ts
#EXTINF:25.00,
http://example.com/2019-04-11_10-52-48.ts
#EXT-X-ENDLIST
As for black videos themselves, I tried several options: each link was to the same file; each link was to a different symlink to the same file; each link was to a separately generated black video - none of them worked.
As of now the only way I found is to collect all normal videos for the time range, fill the gaps with black video files and then combine them into one file with ffmpeg -f concat and split the concatenated file back to parts. But this approach works way longer than manual m3u8 file creation, so I would like to avoid it.
So, what could be the reason of manually formed playlist not working correctly and how could I fix that? May it be the problem with playlist itself, or playlist is technically fine but players I used possibly don't fully implement the specification?
TLDR: I am creating m3u8 playlist manually and I want to insert the same video multiple times into this playlist. Unfortunately, such playlist is not being played correctly: depending on player either this inserted video is being played only once no matter how many times has it been included, or playing is getting stuck after the first inserted video part. May it be that there is something wrong with playlist and how can this be fixed?
Add a #EXT-X-DISCONTINUITY tag before and after black_video.ts file and change the #EXT-X-VERSION tag to 5. That should fix the issue. This solution worked for me on VLC player.
I am trying to play back the audio which was captured using waspi capture. The audio is saved in the form of wasapicapture.in file. Now the challenge is to play back the audio captured using wasapi renderer. I am able to play back, but the audio which I listen is always in stereo like, so its faster. I would like to reproduce that in original format. Could any help me please.
Thanks,
Read the file as Rawstream , pass in the WaveFormat the audio so that you can get the original recordered clarity aswell.
You could either save it into a .WAV file in the first place with WaveFileWriter, which will simplify playing it back. Or you can just read the file and pass it into a RawSourceWaveStream also passing in the WaveFormat the audio was originally recorded in.
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I am trying to understand how mpd file plays and i am referring to the following data set:
http://www-itec.uni-klu.ac.at/ftp/datasets/mmsys12/Valkaama/MPDs/Valkaama_1s_act_isoffmain_DIS_23009_1_v_2_1c2_2011_08_30.mpd
In mpd file format there is segment base consists of mp4 chunk and within it has chunk list with extension .m4s.I downloaded mpd file using :
http://www-itec.uni-klu.ac.at/ftp/datasets/mmsys12/Valkaama/valkaama_1s/valkaama_1s_50kbit/valkaama_50kbit_dash.mp4
and m4s chunk by following link:
http://www-itec.uni-klu.ac.at/ftp/datasets/mmsys12/Valkaama/valkaama_1s/valkaama_1s_50kbit/valkaama_1s1.m4s
I tried to play both mp4 and m4s in vlc player but not able to play any of these two so i want to ask which of the chunk links in the mpd file forma i can be able to play standalone in vlc player.
Please correct me if any of my observations is wrong:
Regards
Mayank
MPD file is just a index of streams with various formats in order to adapt to your bandwidth, to get more information follow the links of the other answers here.
It's possible to download all streams and merge them into a single file, you could achieve this by using youtube-dl:
youtube-dl http://URL/TO/manifest.mpd
You can get more information in https://stackoverflow.com/a/39931712/1522342.
Also, VLC 3.0.0+ can play that kind of file from a url, just open VLC, use the shortcut CTRL+N, paste the url and enjoy.
A DASH player plays an MPD by selecting a Period, and in the Period one or more AdaptationSet, and then one Representation per AdaptationSet. For the chosen Representation, it downloads and passes the intialization segment and some media segments to the media engine. As indicated by others you can simulate that by concatenating (simply using caton Linux).
The MPEG-DASH standard requires that initialization segments (in your case the mp4 file) contain no data. This is because when switching the player might use several times the initialization segment. You can open it in a player but it does not contain any media.
For m4s files, they contain media data but they cannot be interpreted without the associated initialization segment.
you can download init segment (SegmentBase/Initialization#sourceURL) and all media segments (SegmentList/SegmentURL#media) and concatenate everything (e.g. with the copy command on windows). The result should be playable on VLC. This has to be done for audio and video separately. In the next step you can then use MP4Box or similar tools to mux audio and video.
Alternatively you can use www.dash-downloader.com to download everything in one step. The page will display some log explaining what it's doing. That might be helpfull.
(full disclosure: that's my website).
I dont think it is possible to play any of the files in a standalone player. The mp4 is the init segment which is required to decode the .m4s media segments. I dont think there is an option in the vlc player to map an init segment to multiple media segments. Nevertheless you can try a Dash player to play the manifest file. For instance dash.js
Initialization segment: A sequence of bytes that contain all of the initialization information required to decode a sequence of media segments. This includes codec initialization data, Track ID mappings for multiplexed segments, and timestamp offsets (e.g. edit lists).
Media segment: A sequence of bytes that contain packetized & timestamped media data for a portion of the media timeline. Media segments are always associated with the most recently appended initialization segment.
Source: http://www.w3.org/TR/media-source/#init-segment
I'm using sox to convert some mp3 files to wav for a project. The problem is that the software that plays the files does not have the media name for the element it is playing. I can't seem to find a win32 cli tool to read the header of the wav file and write what I need to it.
Sox will read the header but it's not showing the title of the media element that was inserted with the old software I used. I just couldnt automate it or I would have used it instead.
I have determined the info is written in either CART CHUNK section or just to the file headers. I can't figure out to write my own data there.
The way I was able to do this was with this project: https://github.com/JamesHeinrich/getID3
How do you display audio files like an imagepicker? I'm using the MPMediaplayer class but I can't get it to work. My requirement is to click on a tableviewcell, and have audio files appear like an imagepicker.
simple get the path of all audio files. and parse the name only from the path. store all the names in array and display in UITableView. just read about how to use nsfilemanager.