Android and JNI, pipe data to FFmpeg

Question

I'm trying to create a metadata retriever based on FFmpeg. Since raw Android application resources are often only accessible using a file descriptor I need a way to pipe this data to FFmpeg via JNI. I know FFmpeg supports a "pipe" protocol:

UNIX pipe access protocol.

Allow to read and write from UNIX pipes.

The accepted syntax is: 

    pipe:[number]

number is the number corresponding to the file descriptor of the pipe (e.g. 0 for stdin, 1 for stdout, 2 for stderr). If number is not specified, by default the stdout file descriptor will be used for writing, stdin for reading.

For example: cat test.wav | ffmpeg -i pipe:0

My question is, how do I programmatically emulate cat test.wav | ffmpeg -i pipe:0 using JNI and avformat_open_input using a FileDescriptor? Is this possible?

I'm not sure I understand what you are asking, can you rephrase the question? — William Seemann, Mar 25 '14 at 03:58
I wanna ask how to create a named pipe in Java Layer, and pass on JNI — Crossle Song, Mar 25 '14 at 04:03

score 1 · Answer 1 · edited May 23 '17 at 12:23

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People from AndroidFFmpeg project implemented "jni://" protocol to stream data via JNI, see https://github.com/appunite/AndroidFFmpeg/blob/master/FFmpegLibrary/jni/jni-protocol.c

I do not know how it's used, just I came across that file and saw your question. I think you could use the same solution.

You may want to look at this post: https://stackoverflow.com/a/24747137/1028256 about passing FileDescriptor to JNI

edited May 23 '17 at 12:23

Community

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answered Dec 02 '14 at 17:30

Mixaz

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`You may want to look at this post...` You referred him to his own post. – ClassA Feb 13 '20 at 13:23

Android and JNI, pipe data to FFmpeg

1 Answers1