if FFmpegFrameGrabberSimple(inputStream) not use grabber.setFrameNumber(num)

[duck123456]

ByteArrayInputStream inputStream= new ByteArrayInputStream(inputBytes);

    FFmpegFrameGrabberSimple grabber=new FFmpegFrameGrabberSimple(inputStream);
    grabber.start();
    log.info("===>>"+grabber.getLengthInTime());  this is 0
    Frame frame=null;
    int index=0;
    AVPacket pkt=null;
    while(true){
    grabber.setFrameNumber(index);

        frame=  grabber.grabFrame(false,true,true,false);

      index+=38;

    }

Caused by: org.bytedeco.javacv.FrameGrabber$Exception: avformat_seek_file() error -1: Could not seek file to timestamp 2920000.

https://github.com/bytedeco/javacv/blob/master/src/main/java/org/bytedeco/javacv/FFmpegFrameGrabber.java#L619

https://github.com/bytedeco/javacv/blob/master/src/main/java/org/bytedeco/javacv/FFmpegFrameGrabber.java#L812-L814

if use avformat_alloc_context AND avio_alloc_context to Allocating memory will not seek frames

thanks

[saudet]

setFrameNumber() won't work well for streams with variable frame rates. Try to use setTimestamp() instead.

[duck123456]

setFrameNumber() won't work well for streams with variable frame rates. Try to use setTimestamp() instead.
The same problem !

[saudet]

Well, you'll need to give me something to reproduce this issue if you expect some help.

[duck123456]

public static void main(String[] args) throws FileNotFoundException, FrameGrabber.Exception {
    File file=new File("C:\\Users\\x1c\\Desktop\\temp\\49\\pp\\zao_17.ts");
    InputStream inputStream= new FileInputStream(file);
    FFmpegFrameGrabber grabber=new FFmpegFrameGrabber(inputStream);
    grabber.start();
    grabber.setFrameNumber(5);
    Frame frame= grabber.grabFrame(false,true,true,false);
     
}

this simple demo can reproduce the problem! you can try it ! thanks

[saudet]

Ah, that's the problem. .ts files don't have an index. You'll need to convert that to something else first.

[duck123456]

Ah, that's the problem. .ts files don't have an index. You'll need to convert that to something else first.

good! thanks

[duck123456]

public static void main(String[] args) throws FileNotFoundException, FrameGrabber.Exception {
File file=new File("C:\Users\x1c\Desktop\temp\49\pp\zao_17.ts");
FFmpegFrameGrabber grabber=new FFmpegFrameGrabber(file);
grabber.start();
grabber.setFrameNumber(5);
Frame frame= grabber.grabFrame(false,true,true,false);
}

.ts files don't have an index，why InputStream Instead of File is normal ?

[saudet]

Either work the same for me. I'll need something to reproduce that if it doesn't work for you for some reason.

[duck123456]

Either work the same for me. I'll need something to reproduce that if it doesn't work for you for some reason.

.ts file doesn't work,but .mp4 file is normal ! I found that avformat_find_stream_info() doesn't work by .ts file! Either work the same for me!but it work no same! It's confusing to me

[saudet]

You're right, it isn't working the same for MPEG-TS. It feels like there is a bug in FFmpeg somewhere there, and should probably be reported upstream...

[duck123456]

You're right, it isn't working the same for MPEG-TS. It feels like there is a bug in FFmpeg somewhere there, and should probably be reported upstream...

Well,thanks

[saudet]

Actually, after implementing AVSEEK_SIZE, it appears to work fine!

[duck123456]

Actually, after implementing AVSEEK_SIZE, it appears to work fine!

Awesome ！it appears to work fine! that is cool ！Thank you

[saudet]

Fix now included in JavaCV 1.5.1. Thanks for reporting!