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  • ffmpeg used vda from os x

    13 mai 2014, par user2618420

    I try to enable hardware decoding project earlier decoded using ffmpeg

    ffmpeg has support in hard-copy decoding
    Here documentation kotoroya I did https://github.com/dilaroga/ffmpeg-vda/wiki/FFmpeg-vda-usage
    my code

    enum AVPixelFormat myGetFormatCallback(struct AVCodecContext *ctx, const enum AVPixelFormat * fmt)
    
{
    
    struct vda_context *vda_ctx;
    
    vda_ctx = (struct vda_context *)malloc(sizeof(vda_context));
    
    vda_ctx->decoder = NULL;
    
    vda_ctx->width = ctx->width;
    
    vda_ctx->height = ctx->height;
    
    vda_ctx->format = 'avc1';
    
    vda_ctx->use_ref_buffer = 1;
    
    switch (ctx->pix_fmt) {
    
        case PIX_FMT_UYVY422:{
    
            vda_ctx->cv_pix_fmt_type = '2vuy';
    
            break;
    
        }
    
        case PIX_FMT_YUYV422:{
    
            vda_ctx->cv_pix_fmt_type = 'yuvs';
    
            break;
    
        }
    
        case PIX_FMT_NV12:{
    
            vda_ctx->cv_pix_fmt_type = '420v';
    
            break;
    
        }
    
        case PIX_FMT_YUV420P:{
    
            vda_ctx->cv_pix_fmt_type = 'y420';
    
            break;
    
        }
    
        default:{
    
            av_log(ctx, AV_LOG_ERROR, "Unsupported pixel format: %d\n", ctx->pix_fmt);
    
            Logger::debug(LOG_LEVEL_ERROR, "Unsupported pixel format: %d", ctx->pix_fmt);
    
            throw AbstractException("Unsupported pixel format");
    
        }
    
     }
    
    int status = ff_vda_create_decoder(vda_ctx, (unsigned char*)ctx->extradata,ctx->extradata_size);
    
    if (status){
    
        Logger::debug(LOG_LEVEL_ERROR, "Error create VDA decoder");
    
        throw AbstractException("Error create VDA decoder");
    
    }else{
    
        ctx->hwaccel_context = vda_ctx;
    
    }
    

    
    return ctx->pix_fmt;
    
}
    

    
static void release_vda_context(void *opaque, uint8_t *data)
    
{
    
    vda_buffer_context *vda_context = (vda_buffer_context *)opaque;
    
    av_free(vda_context);
    
}
    

    
int myGetBufferCallback(struct AVCodecContext *s, AVFrame *av_frame, int flags)
    
{
    
    vda_buffer_context *vda_context = (vda_buffer_context *)av_mallocz(sizeof(*vda_context));
    
    AVBufferRef *buffer = av_buffer_create(NULL, 0, release_vda_context, vda_context, 0);
    

    
    if( !vda_context || !buffer )
    
    {
    
        av_free(vda_context);
    
        return -1;
    
    }
    

    
    av_frame->buf[0] = buffer;
    
    av_frame->data[0] = (uint8_t*)1;
    
    return 0;
    
}
    

    

    
static void release_buffer(struct AVCodecContext *opaque, AVFrame *pic)
    
{
    
    vda_buffer_context *context = (vda_buffer_context*)opaque;
    
    CVPixelBufferUnlockBaseAddress(context->cv_buffer, 0);
    
    CVPixelBufferRelease(context->cv_buffer);
    
    av_free(context);
    
}
    

    
main(){
    
    //init ff context
    
    if (avcodec_open2(mCodecContext, mCodec, NULL) < 0) throw AbstractException("Unable to open codec");
    

    
    mCodecContext->get_format = myGetFormatCallback;
    
    mCodecContext->get_buffer2 = myGetBufferCallback;
    
    mCodecContext->release_buffer = release_buffer;
    
}

    but I did not myGetFormatCallback the method is called, and called myGetBufferCallback falls
    why not called myGetFormatCallback ? what’s wrong ? may not work well at all

  • libx264 encoder video plays too fast

    23 avril 2014, par Nick

    I’m trying to write a program that uses libx264 to encode the video frames. I’ve wrapped this code into a small class (see below). I have frames that are in YUV420 format. libx264 encodes the frames and I save them to a file. I can play the file back in VLC, all of the frames are there, but it plays back at several hundred times the actual frame rate. Currently I am capturing frames at 2.5 FPS, but they play back as if it was recorded at 250 or more FPS. I’ve tried to change the frame rate with no luck.

    I’ve also tried to set

    _param.b_vfr_input = 1

    and then set the time bases appropriately, but that causes my program to crash. Any ideas ? My encode code is shown below. I’ve also included the output of ffprobe -show_frames

    Wrapper Class :

    x264wrapper::x264wrapper(int width, int height, int fps, int timeBaseNum, int timeBaseDen, int vfr)
    
{
    
    x264_param_default_preset(&_param, "veryfast", "zerolatency");
    
    _param.i_threads = 1;
    
    _param.i_width = width;
    
    _param.i_height = height;
    
    _param.i_fps_num = fps;
    
    _param.i_fps_den = 1;
    
    // Intra refres:
    
    _param.i_keyint_max = fps;
    
    _param.b_intra_refresh = 1;
    
    //Rate control:
    
    _param.rc.i_rc_method = X264_RC_CRF;
    
    //_param.rc.i_rc_method = X264_RC_CQP;
    
    _param.rc.f_rf_constant = 25;
    
    _param.rc.f_rf_constant_max = 35;
    
    //For streaming:
    
    _param.b_repeat_headers = 1;
    
    _param.b_annexb = 1;    
    
    // misc
    
    _param.b_vfr_input = vfr;
    
    _param.i_timebase_num = timeBaseNum; 
    
    _param.i_timebase_den = timeBaseDen;
    

    
    _param.i_log_level = X264_LOG_DEBUG;
    

    
    _encoder = x264_encoder_open(&_param);
    

    
    cout << "Timebase " << _param.i_timebase_num << "/" << _param.i_timebase_den << endl;
    
    cout << "fps " << _param.i_fps_num << "/" << _param.i_fps_den << endl;
    
    _ticks_per_frame = (int64_t)_param.i_timebase_den * _param.i_fps_den / _param.i_timebase_num / _param.i_fps_num;
    
    cout << "ticks_per_frame " << _ticks_per_frame << endl;
    
    int result = x264_picture_alloc(&_pic_in, X264_CSP_I420, width, height);
    
    if (result != 0)
    
    {
    
        cout << "Failed to allocate picture" << endl;
    
        throw(1);
    
    }
    

    
    _ofs = new ofstream("output.h264", ofstream::out | ofstream::binary);
    
    _pts = 0;
    
}
    

    

    
x264wrapper::~x264wrapper(void)
    
{
    
    _ofs->close();
    
}
    

    

    

    
void x264wrapper::encode(uint8_t * buf)
    
{
    
    x264_nal_t* nals;
    
    int i_nals;
    
    convertFromBalserToX264(buf);
    
    _pts += _ticks_per_frame;
    
    _pic_in.i_pts = _pts;
    
    x264_picture_t pic_out;
    
    int frame_size = x264_encoder_encode(_encoder, &nals, &i_nals, &_pic_in, &pic_out);
    
    if (frame_size >= 0)
    
    {
    
        _ofs->write((char*)nals[0].p_payload, frame_size);
    
    }
    
    else
    
    {
    
        cout << "error: x264_encoder_encode failed" << endl;
    
    }
    
}

    Output of ffprobe -show_frames :

    [FRAME]
    
media_type=video
    
key_frame=1
    
pkt_pts=N/A
    
pkt_pts_time=N/A
    
pkt_dts=N/A
    
pkt_dts_time=N/A
    
pkt_duration=48000
    
pkt_duration_time=0.040000
    
pkt_pos=0
    
width=1920
    
height=1080
    
pix_fmt=yuv420p
    
sample_aspect_ratio=N/A
    
pict_type=I
    
coded_picture_number=0
    
display_picture_number=0
    
interlaced_frame=0
    
top_field_first=0
    
repeat_pict=0
    
reference=0
    
[/FRAME]
    
[FRAME]
    
media_type=video
    
key_frame=0
    
pkt_pts=N/A
    
pkt_pts_time=N/A
    
pkt_dts=N/A
    
pkt_dts_time=N/A
    
pkt_duration=N/A
    
pkt_duration_time=N/A
    
pkt_pos=54947
    
width=1920
    
height=1080
    
pix_fmt=yuv420p
    
sample_aspect_ratio=N/A
    
pict_type=P
    
coded_picture_number=1
    
display_picture_number=0
    
interlaced_frame=0
    
top_field_first=0
    
repeat_pict=0
    
reference=0
    
[/FRAME]
    
[FRAME]
    
media_type=video
    
key_frame=0
    
pkt_pts=N/A
    
pkt_pts_time=N/A
    
pkt_dts=N/A
    
pkt_dts_time=N/A
    
pkt_duration=N/A
    
pkt_duration_time=N/A
    
pkt_pos=57899
    
width=1920
    
height=1080
    
pix_fmt=yuv420p
    
sample_aspect_ratio=N/A
    
pict_type=P
    
coded_picture_number=2
    
display_picture_number=0
    
interlaced_frame=0
    
top_field_first=0
    
repeat_pict=0
    
reference=0
    
[/FRAME]

  • OpenCV Java binds VideoCapture from file failing silently

    8 décembre 2014, par muz0

    I’m using OpenCV 2.4.8 with the supplied Windows 64bit Java jar. I’ve been making full use of OpenCV in my current environment up until this point.

    I’m unable to open video files using the
    VideoCapture class however webcam feeds work just fine.

    The below works as expected with video.isOpened returning true

        VideoCapture video = new VideoCapture();
    
    boolean result = video.open(0);

    The below fails with video.isOpened returning false

        VideoCapture video = new VideoCapture();
    
    boolean result = video.open("res/hand-test-1.mp4");

    Neither file formats seems to make a difference (These are converted, not just renamed in hope)

        video.open("res/hand-test-1.mp4");
    
    video.open("res/hand-test-1.avi");
    
    video.open("res/hand-test-1.wmv");

    Location seems to matter not either.

        video.open("C:/hand-test-1.mp4");
    
    video.open("C:\\hand-test-1.mp4");
    
    video.open("hand-test-1.mp4");

    Neither does garbage, no exception kicked up from OpenCV through Java either, seems to fail silently.

        video.open("ashdkfhkajsjdfkhaksdf");

    PATH contains the ffmpeg directory supplied with the opencv installation,

        C:\dev\opencv\sources\3rdparty\ffmpeg

    Right now I’ve run out of ideas, it seems like whatever I throw to the native via video.open(String) will return false.

    Any help would be much appreciated

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