Which formats does MPMoviePlayerController Support?
According to the documentation:
Supported Formats
This class plays any movie or audio file supported in iOS. This includes both streamed content and fixed-length files. For movie files, this typically means files with the extensions .mov, .mp4, .mpv, and .3gp and using one of the following compression standards:
H.264 Baseline Profile Level 3.0 video, up to 640 x 480 at 30 fps. (The Baseline profile does not support B frames.)
MPEG-4 Part 2 video (Simple Profile)
If you use this class to play audio files, it displays a white screen with a QuickTime logo while the audio plays. For audio files, this class supports AAC-LC audio at up to 48 kHz, and MP3 (MPEG-1 Audio Layer 3) up to 48 kHz, stereo audio.
Related
I need an audio steganalysis tool for detecting stego mp3 files.
There is an audio steganalysis tools (MP3stego), but its input is for wav stego files. Also there are some audio steganalysis algorithms that refers to MP3stego.
i need the audio file for the yuv test video sequences like foreman.yuv, akiyo.yuv
,etc. none of the yuv sequences online have the audio file.
any other yuv sequences with the audio file suitable for encoder analysis also works.
I think there is no audio available for the sequences you mention.
But have a look at https://media.xiph.org/video/derf/, at the bottom of the page you have full sequences with flac audio.
Is there a case where a video file could contain both mjpeg frames and a sound layer? I know originally, people used to place a 8khz PCM uncompressed track along with their mjpeg movie since it is streamed/decoded/played frame by frame with no motion prediction needed. Can some decoder accept an Mjpeg with a more recent audio format?
[EDIT 1]
What I'll first try is to check if ffmpeg handles the conversion of Audio/Video movies to MJpeg with audio, and I'll explore the header and the layers with an hex editor.
[EDIT 2]
OK. I've studied a Mjpeg with audio:
ffmpeg -i some_movie_with_music.mp4 -f avi -acodec mp3 -vcodec mjpeg mjpegWithSound.avi
And there's an MP3 file splitted into the total number of frames under each jpeg plus some changes in the header. So it's easy to implement in a context where a mobile application would offer to the user the opportunity to add an MP3 files to a serie of jpeg or to a movie. So, one more reason to use Mjpeg when a platform has no encoder yet.
It's fun to watch your application take shape. :-) I'm going to assume this is a follow-on to your last question and that you want to write C# code to accomplish this task. Are you still writing this into an AVI container? AVI stands for "audio/video interleaved" and is designed to transport both audio and video.
So, yes, you should be able to write both MJPEG and audio into an AVI file.
Guess what! You have lots of options for audio codecs too. We haven't cataloged quite as many audio codecs as video codecs (but close). Good news, though: Implementing a basic audio encoder in pure C# should be much simpler than trying to port even an MPEG-1 video encoder. Alternatively, check around to see if you can find an MP3 encoder written in pure C#. AVI accommodates MP3. If not, try IMA ADPCM. It's easy to implement and gives you 4:1 compression. Thus, if you have a monophonic, 44100 Hz, 16-bit stream, that requires 88200 bytes/sec. IMA ADPCM will give you roughly 22050 bytes/sec (plus small overhead).
I am writing an encoding software and dealing with uncompressed wav and flac formats. My question is, flac is supposed to be a lossless format, similar to wav but compressed. However, certain softwares such as JRiver's Media Center offer a 'quality' setting for encoding flac files. Does taht mean they are offering to reduce quality pre-encoding or am i missing something in the flac standard?
The quality parameter for FLAC refers to the quality of compression, not audio. The audio will stay lossless but you get a better compression with higher quality. Higher quality will take more time to compress however.
See docs http://wiki.jriver.com/index.php/Encoding_Settings
Free Lossless Audio Codec (FLAC): FLAC is a popular lossless, freely
available open source encoder. [2] Quality Settings: 0 - 8. Sets the
quality of compression (and not sound, which is lossless), 8 meaning
most compressed/time/effort.
What audio formats are supported by DICOM as per DICOM standards?
DICOM Supplement 30 added support for waveforms to the DICOM Standard. Included in this is support for audio waveforms.
Also, there was the addition of support for MPEG2 video in DICOM Supplement 42. This video support allows encoding of mp3 data within the video stream.
Just for completeness, since the question is a little older:
Supplement 30 indeed added support for audio with the Basic Voice(!) Audio object. However, it only supports 8000 Hz sampling frequency.
Therefore later on DICOM introduced the General Audio Waveform object that permits up to 44,100 Hz.
Both objects are restricted to two audio channels,i.e. permit mono or stereo recordings. You can find information about them in part 3 of the DICOM standard.
Furthermore, DICOM also supports not only MPEG2 but also MPEG4 video. Look into DICOM part 5 for further information.
Michael