Using MediaCodec, how can I generate key i-frames with interval less than 1 second?

Question

MediaFormat.KEY_I_FRAME_INTERVAL only takes an integer value, and I assume this is what controls how frequent the encoder generates an I-frame right? So does that mean if I am using MediaCodec I cannot possibly generate I-frames more frequently?

Here's [a link](https://stackoverflow.com/a/58933377/10960892) to my answer to similar question: — puksec, Nov 19 '19 at 11:51
Here's a link to my answer to the similar question: https://stackoverflow.com/a/58933377/10960892 — puksec, Nov 19 '19 at 11:52

score 2 · Accepted Answer · answered Sep 22 '16 at 03:04

I finally found a workaround for this issue!

Insert the following code before a key frame is needed, then it will generate a key frame on the next available frame.

        Bundle b = new Bundle();
        b.putInt(MediaCodec.PARAMETER_KEY_REQUEST_SYNC_FRAME, 0);
        encoder.setParameters(b);

score 1 · Answer 2 · answered Aug 27 '16 at 20:01

You can probably work around this by scaling your timestamps. If you e.g. multiply the timestamps by 2 when inputting them into the encoder, and then divide by 2 on the timestamps you get on the output buffers from the encoder, you should be able to get an I-frame interval of half a second. Then you also need to halve the bitrate (and frame rate) to make it match. This isn't ideal of course, but should allow you to get the right effect.

very interesting solution! – Oleg Sokolov Nov 08 '17 at 11:21 — Oleg Sokolov, Nov 08 '17 at 11:21

score 0 · Answer 3 · answered Nov 08 '17 at 11:34

The documentation says that:

A zero value means a stream containing all key frames is requested.

So all what you need is:

MediaFormat format = MediaFormat.createVideoFormat(...);
format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 0);

It works for some devices, but for some devices (Nexus 6p for example) it produces exception:

E/ACodec: [OMX.qcom.video.encoder.avc] configureCodec returning error -1010
E/ACodec: signalError(omxError 0x80001001, internalError -1010) 
E/MediaCodec: Codec reported err 0xfffffc0e, actionCode 0, while in state 3
E/MediaCodec: configure failed with err 0xfffffc0e, resetting...

Valerio · Answer 4 · 2020-09-19T16:11:42.160

KEY_I_FRAME_INTERVAL can also receive float since Android 7.1.

Therefore is now possible to do something like this :

val mediaFormat: MediaFormat = MediaFormat.createVideoFormat(VIDEO_MIME_TYPE, 480, 640)
// 30 Frames per second
mediaFormat.setInteger(MediaFormat.KEY_FRAME_RATE, 30) 
// 1 second between key frames!
mediaFormat.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 1) 
// 0.3 seconds between key frame!
mediaFormat.setFloat(MediaFormat.KEY_I_FRAME_INTERVAL, 0.3F)

Using MediaCodec, how can I generate key i-frames with interval less than 1 second?

4 Answers4