MareArts Computer Vision Study.: C++ code example for fast display of 8K video using VDPAU/DXVA

2/17/2023

C++ code example for fast display of 8K video using VDPAU/DXVA

refer to code:

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <unistd.h>
#include <vdpau/vdpau.h>
#include <vdpau/vdpau_x11.h>

using namespace std;

int main(int argc, char **argv) {
    if (argc < 2) {
        cerr << "Usage: " << argv[0] << " <video file>" << endl;
        exit(1);
    }

    VdpDevice device;
    VdpStatus status;
    status = vdp_device_create_x11(DefaultDisplay(), DefaultScreen(DefaultDisplay()), &device, nullptr);
    if (status != VDP_STATUS_OK) {
        cerr << "vdp_device_create_x11 failed: " << status << endl;
        exit(1);
    }

    VdpVideoSurface surface;
    status = vdp_video_surface_create(device, VDP_CHROMA_TYPE_420, 8192, 4320, &surface);
    if (status != VDP_STATUS_OK) {
        cerr << "vdp_video_surface_create failed: " << status << endl;
        exit(1);
    }

    VdpDecoder decoder;
    status = vdp_decoder_create(device, VDP_DECODER_PROFILE_H264_HIGH, 8192, 4320, 16, &decoder);
    if (status != VDP_STATUS_OK) {
        cerr << "vdp_decoder_create failed: " << status << endl;
        exit(1);
    }

    FILE *file = fopen(argv[1], "rb");
    if (!file) {
        cerr << "Failed to open video file: " << argv[1] << endl;
        exit(1);
    }

    uint8_t *buf = new uint8_t[65536];
    while (!feof(file)) {
        size_t n = fread(buf, 1, 65536, file);
        VdpBitstream bitstream = { buf, n };
        status = vdp_decoder_decode(decoder, surface, &bitstream, 0, 0);
        if (status != VDP_STATUS_OK) {
            cerr << "vdp_decoder_decode failed: " << status << endl;
            exit(1);
        }
    }

    fclose(file);

    VdpPresentationQueue presentation_queue;
    status = vdp_presentation_queue_create(device, DefaultVisual(DefaultDisplay(), DefaultScreen(DefaultDisplay())), &presentation_queue);
    if (status != VDP_STATUS_OK) {
        cerr << "vdp_presentation_queue_create failed: " << status << endl;
        exit(1);
    }

    VdpOutputSurface output_surface;
    status = vdp_output_surface_create(device, VDP_RGBA_FORMAT_B8G8R8A8, 8192, 4320, &output_surface);
    if (status != VDP_STATUS_OK) {
        cerr << "vdp_output_surface_create failed: " << status << endl;
        exit(1);
    }

    VdpPresentationQueueTarget presentation_queue_target;
    status = vdp_presentation_queue_target_create_x11(presentation_queue, DefaultScreen(DefaultDisplay()), DefaultVisual(DefaultDisplay(), DefaultScreen(DefaultDisplay())), &presentation_queue_target);
    if (status != VDP_STATUS_OK) {
        cerr << "vdp_presentation_queue_target_create_x11 failed: " << status << endl;
        exit(1);
    }

    VdpTimebase timebase;
    status = vdp_timebase_create(device, 1, &timebase);
    if (status != VDP_STATUS_OK) {
        cerr << "vdp_timebase_create failed: " << status << endl;
        exit(1);
    }

    VdpOutputSurfaceRenderBlendState blend_state = { VDP_OUTPUT_SURFACE_RENDER_BLEND_STATE_OPAQUE };
    VdpOutputSurfaceRenderBlendState blend_state_array[1] = { blend_state };
    VdpOutputSurfaceRenderBlendState *blend_states = blend_state_array;
    VdpColor color = { 0, 0, 0, 0 };
    VdpRect src_rect = { 0, 0, 8192, 4320 };
    VdpRect dst_rect = { 0, 0, 1920, 1080 };
    VdpTime presentation_time = 0;

    while (true) {
        status = vdp_presentation_queue_block_until_surface_idle(presentation_queue, output_surface, &presentation_time);
        if (status != VDP_STATUS_OK) {
            cerr << "vdp_presentation_queue_block_until_surface_idle failed: " << status << endl;
            exit(1);
        }

        status = vdp_output_surface_render_output_surface(output_surface, &src_rect, surface, &dst_rect, blend_states, 1, &color);
        if (status != VDP_STATUS_OK) {
            cerr << "vdp_output_surface_render_output_surface failed: " << status << endl;
            exit(1);
        }

        status = vdp_presentation_queue_display(presentation_queue, presentation_queue_target, presentation_time, timebase);
        if (status != VDP_STATUS_OK) {
            cerr << "vdp_presentation_queue_display failed: " << status << endl;
            exit(1);
        }
    }

    return 0;
}

    

this code creates the presentation queue and target, sets up the output surface rendering, and then enters a loop that continuously displays the video frames using the vdp_presentation_queue_display function.

Please note that this code is just an example and may need to be modified to fit your specific needs.

Thank you.

🙇🏻‍♂️

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