~emersion/vaapi-decoder

5d2a7b78da5d0dec4175aaac56c7ffbca1cc1774 — Simon Ser 9 months ago
Initial commit
4 files changed, 259 insertions(+), 0 deletions(-)

A .gitignore
A LICENSE
A Makefile
A main.c
A  => .gitignore +1 -0
@@ 1,1 @@
/vaapi-decoder

A  => LICENSE +25 -0
@@ 1,25 @@
BSD 2-Clause License

Copyright (c) 2021, Valve Corporation
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

A  => Makefile +11 -0
@@ 1,11 @@
CFLAGS = -g -Wall -Wextra -Wno-unused-parameter
avdeps = libavcodec libavformat libavutil
avflags = $(shell pkg-config $(avdeps) --cflags --libs)

all: vaapi-decoder

vaapi-decoder: main.c
	$(CC) $(CFLAGS) $(avflags) -o $@ $^

clean:
	$(RM) vaapi-decoder

A  => main.c +222 -0
@@ 1,222 @@
#include <stdio.h>
#include <unistd.h>

#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavutil/hwcontext.h>
#include <libavutil/hwcontext_drm.h>
#include <libavutil/pixdesc.h>

static enum AVPixelFormat hw_pix_fmt = AV_PIX_FMT_NONE;

static int check_hw_device_type(enum AVHWDeviceType type) {
	enum AVHWDeviceType t = AV_HWDEVICE_TYPE_NONE;
	while (1) {
		t = av_hwdevice_iterate_types(t);
		if (t == AV_HWDEVICE_TYPE_NONE) {
			break;
		}
		if (t == type) {
			return 0;
		}
	}
	return -1;
}

static enum AVPixelFormat get_hw_format(AVCodecContext *ctx,
		const enum AVPixelFormat *pix_fmts) {
	for (size_t i = 0; pix_fmts[i] != AV_PIX_FMT_NONE; i++) {
		if (pix_fmts[i] == hw_pix_fmt) {
			return hw_pix_fmt;
		}
	}

	fprintf(stderr, "Failed to find HW pixel format\n");
	return AV_PIX_FMT_NONE;
}

static int decode_frame(AVFormatContext *input_ctx, int video_stream,
		AVCodecContext *decoder_ctx, AVFrame **frame_ptr) {
	int ret;
	while (1) {
		AVPacket packet;
		ret = av_read_frame(input_ctx, &packet);
		if (ret < 0) {
			fprintf(stderr, "Failed to read frames into packet\n");
			return ret;
		}

		if (video_stream != packet.stream_index) {
			av_packet_unref(&packet);
			continue;
		}

		ret = avcodec_send_packet(decoder_ctx, &packet);
		if (ret < 0) {
			fprintf(stderr, "Failed to send packet to decoder\n");
			return ret;
		}
		av_packet_unref(&packet);

		AVFrame *frame = av_frame_alloc();
		if (!frame) {
			fprintf(stderr, "Failed to allocate frame\n");
			return AVERROR(ENOMEM);
		}

		while (1) {
			ret = avcodec_receive_frame(decoder_ctx, frame);
			if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
				break;
			} else if (ret < 0) {
				fprintf(stderr, "Failed to receive frame from decoder\n");
				return ret;
			}

			if (frame->format != hw_pix_fmt) {
				continue;
			}

			*frame_ptr = frame;
			return 0;
		}

		av_frame_free(&frame);
	}

	return AVERROR_EOF;
}

int main(int argc, char *argv[]) {
	if (argc < 2) {
		fprintf(stderr, "usage: %s <file>\n", argv[0]);
		return 1;
	}

	enum AVHWDeviceType type = AV_HWDEVICE_TYPE_VAAPI;
	int ret = check_hw_device_type(type);
	if (ret != 0) {
		fprintf(stderr, "VA-API not supported\n");
		return 1;
	}

	AVFormatContext *input_ctx = NULL;
	if (avformat_open_input(&input_ctx, argv[1], NULL, NULL) != 0) {
		fprintf(stderr, "Failed to open input file\n");
		return 1;
	}

	if (avformat_find_stream_info(input_ctx, NULL) < 0) {
		fprintf(stderr, "Failed to find input stream info\n");
		return 1;
	}

	AVCodec *decoder = NULL;
	int video_stream = av_find_best_stream(input_ctx, AVMEDIA_TYPE_VIDEO,
		-1, -1, &decoder, 0);
	if (video_stream < 0) {
		fprintf(stderr, "Failed to find video stream in input file\n");
		return 1;
	}
	fprintf(stderr, "Selected decoder %s\n", decoder->name);

	int i = 0;
	while (1) {
		const AVCodecHWConfig *config = avcodec_get_hw_config(decoder, i);
		if (!config) {
			fprintf(stderr, "Decoder %s doesn't support device type %s\n",
				decoder->name, av_hwdevice_get_type_name(type));
			return 1;
		}

		if ((config->methods & AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX) &&
				config->device_type == type) {
			hw_pix_fmt = config->pix_fmt;
			break;
		}

		i++;
	}
	fprintf(stderr, "Selected pixel format %s\n", av_get_pix_fmt_name(hw_pix_fmt));

	AVCodecContext *decoder_ctx = avcodec_alloc_context3(decoder);
	if (!decoder_ctx) {
		fprintf(stderr, "Failed to allocate decoder context\n");
		return 1;
	}

	AVStream *video = input_ctx->streams[video_stream];
	if (avcodec_parameters_to_context(decoder_ctx, video->codecpar) < 0) {
		fprintf(stderr, "Failed to fill decoder context from video parameters\n");
		return 1;
	}

	decoder_ctx->get_format = get_hw_format;

	AVBufferRef *hw_device_ctx = NULL;
	ret = av_hwdevice_ctx_create(&hw_device_ctx, type, NULL, NULL, 0);
	if (ret < 0) {
		fprintf(stderr, "Failed to create HW device context\n");
		return 1;
	}
	decoder_ctx->hw_device_ctx = av_buffer_ref(hw_device_ctx);

	ret = avcodec_open2(decoder_ctx, decoder, NULL);
	if (ret < 0) {
		fprintf(stderr, "Failed to open codec for stream #%u\n", video_stream);
		return 1;
	}

	AVFrame *frame = NULL;
	ret = decode_frame(input_ctx, video_stream, decoder_ctx, &frame);
	if (ret < 0) {
		return 1;
	}

	fprintf(stderr, "Got %dx%d frame!\n", frame->width, frame->height);

	AVFrame *drm_frame = av_frame_alloc();
	drm_frame->format = AV_PIX_FMT_DRM_PRIME;
	drm_frame->hw_frames_ctx = av_buffer_ref(frame->hw_frames_ctx);

	// Convert the VA-API frame into a DMA-BUF frame
	ret = av_hwframe_map(drm_frame, frame, 0);
	if (ret < 0) {
		fprintf(stderr, "Failed to map frame: %s\n", av_err2str(ret));
		return 1;
	}

	AVDRMFrameDescriptor *drm_frame_desc = (void *)drm_frame->data[0];
	fprintf(stderr, "DRM frame:\n");
	for (int i = 0; i < drm_frame_desc->nb_objects; i++) {
		AVDRMObjectDescriptor *drm_object = &drm_frame_desc->objects[i];
		fprintf(stderr, "  object #%i: fd = %d, size = %zu, "
			"format_modifier = 0x%lX\n", i, drm_object->fd,
			drm_object->size, drm_object->format_modifier);
	}
	for (int i = 0; i < drm_frame_desc->nb_layers; i++) {
		AVDRMLayerDescriptor *drm_layer = &drm_frame_desc->layers[i];
		fprintf(stderr, "  layer #%d: format = 0x%X\n",
			i, drm_layer->format);
		for (int j = 0; j < drm_layer->nb_planes; j++) {
			AVDRMPlaneDescriptor *drm_plane = &drm_layer->planes[j];
			fprintf(stderr, "    plane #%d: object_index = %d, "
				"offset = %ld, pitch = %ld\n", j, drm_plane->object_index,
				drm_plane->offset, drm_plane->pitch);
		}
	}

	for (int i = 0; i < drm_frame_desc->nb_objects; i++) {
		close(drm_frame_desc->objects[i].fd);
		drm_frame_desc->objects[i].fd = -1;
	}

	av_frame_free(&drm_frame);
	av_frame_free(&frame);

	avcodec_free_context(&decoder_ctx);
	avformat_close_input(&input_ctx);
	av_buffer_unref(&hw_device_ctx);

	return 0;
}