Error when using FFmpegFrameRecorder to concat two MP4 videos

[li310]

I have the same problem merge two mp4 videos, two videos have the same rate
below my code:
FFmpegFrameGrabber grabber1 = new FFmpegFrameGrabber(videoPath+"1.mp4");
FFmpegFrameGrabber grabber2 = new FFmpegFrameGrabber(videoPath+"2.mp4");
FFmpegFrameRecorder recorder = new FFmpegFrameRecorder(videoOutputPath + "output.mp4",1280,720, 2);
grabber1.start();
grabber2.start();
recorder.start(grabber1.getFormatContext());
AVPacket packet1, packet2;
while ((packet1 = grabber1.grabPacket()) != null) {
recorder.recordPacket(packet1);
}
while ((packet2 = grabber2.grabPacket()) != null) {
recorder.recordPacket(packet2);
}
recorder.stop();
grabber1.stop();
grabber2.stop();

and the error:
Exception in thread "main" org.bytedeco.javacv.FrameRecorder$Exception: av_interleaved_write_frame() error -22 while writing interleaved video packet.
at org.bytedeco.javacv.FFmpegFrameRecorder.writePacket(FFmpegFrameRecorder.java:1222)
at org.bytedeco.javacv.FFmpegFrameRecorder.recordPacket(FFmpegFrameRecorder.java:1255)
at javacvdemo.VideoProcessing.packetRecord(VideoProcessing.java:177)
at javacvdemo.Application.main(Application.java:20)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'F:\work\javacvdemo\1.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf58.20.100
Duration: 00:00:03.86, start: 0.000000, bitrate: 701 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 665 kb/s, 26 fps, 26 tbr, 13312 tbn, 52 tbc (default)
Metadata:
handler_name : 片头.mp4.vc.264#video - Imported with GPAC 0.5.1-DEV-rev4102M
Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 16000 Hz, mono, fltp, 37 kb/s (default)
Metadata:
handler_name : SoundHandler
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'F:\work\javacvdemo\2.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf58.20.100
Duration: 00:00:09.66, start: 0.000000, bitrate: 989 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 946 kb/s, 26 fps, 26 tbr, 13312 tbn, 52 tbc (default)
Metadata:
handler_name : 正前 Comp 1.mp4.vc.264#video - Imported with GPAC 0.5.1-DEV-rev4102M
Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 16000 Hz, mono, fltp, 37 kb/s (default)
Metadata:
handler_name : SoundHandler
[mp4 @ 00000000205a7bc0] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
[mp4 @ 00000000205a7bc0] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
Output #0, mp4, to 'F:\work\javacvdemo\output.mp4':
Metadata:
encoder : Lavf58.20.100
Stream #0:0: Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], q=2-31, 665 kb/s, 26 fps, 13312 tbn, 26 tbc
Stream #0:1: Audio: aac (LC) (mp4a / 0x6134706D), 16000 Hz, mono, fltp, 37 kb/s
[mp4 @ 00000000205a7bc0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49152 >= -1024

[saudet]

It just looks like you need to give the packets proper timestamps:

[mp4 @ 00000000205a7bc0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 49152 >= -1024

But if that still doesn't work, see issue #818.