render nv12 issues

[w136111526]

Hello, can I use a simple SDL player to play nv12 data without hard decoding nv12, why use USE_HWACCEL hard decoding to convert to nv12, SDL playing rendering is not normal. My code is as follows:

#include <stdio.h>

#include "windows.h"

#include "ffmpeg_dxva2.h"

#define __STDC_CONSTANT_MACROS

extern "C"
{
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libswscale/swscale.h"
#include "libavdevice/avdevice.h"
#include "libavutil/avutil.h"
#include "libavutil/imgutils.h"
#include "libavfilter/avfilter.h"
#include "SDL/SDL.h"
};

#define USE_HWACCEL 0

static FILE *output_file = NULL;

int main(int argc, char* argv[])
{
AVFormatContext *pFormatCtx;
int i, videoindex;
AVCodecContext *pCodecCtx;
AVCodec *pCodec;
AVFrame *pFrame,pFrameTarget;
AVFramesw_frame = NULL;
uint8_t *out_buffer;
AVPacket *packet;
int y_size;
int ret, got_picture;
struct SwsContext *img_convert_ctx = nullptr;

char filepath[]="e:/1.MP4";
//SDL---------------------------
int screen_w=0,screen_h=0;
SDL_Window *screen; 
SDL_Renderer* sdlRenderer;
SDL_Texture* sdlTexture;

avcodec_register_all();
av_register_all();
avdevice_register_all();
pFormatCtx = avformat_alloc_context();

if(avformat_open_input(&pFormatCtx,filepath,NULL,NULL)!=0)
{
	printf("Couldn't open input stream.\n");
	return -1;
}
if(avformat_find_stream_info(pFormatCtx,NULL)<0){
	printf("Couldn't find stream information.\n");
	return -1;
}

videoindex=-1;
for(i=0; i<pFormatCtx->nb_streams; i++) 
	if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO){
		videoindex=i;
		break;
	}
if(videoindex==-1){
	printf("Didn't find a video stream.\n");
	return -1;
}
auto videoStream = pFormatCtx->streams[videoindex];

pCodecCtx=pFormatCtx->streams[videoindex]->codec;
pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
if(pCodec==NULL){
	printf("Codec not found.\n");
	return -1;
}

#if USE_HWACCEL
////Add HwAccel
InputStream *ist = new InputStream();
ist->hwaccel_id = HWACCEL_AUTO;
ist->hwaccel_device = "dxva2";
ist->dec = pCodec;
ist->dec_ctx = pCodecCtx;

pCodecCtx->opaque = ist;
if (dxva2_init(pCodecCtx) >= 0)
{
	pCodecCtx->get_buffer2 = ist->hwaccel_get_buffer;
	pCodecCtx->get_format = GetHwFormat;
	pCodecCtx->thread_safe_callbacks = 1;
	pCodecCtx->thread_count = 1;  // Multithreading is apparently not compatible with hardware decoding
}
else
{
	delete ist;
	pCodecCtx->opaque = nullptr;
	pCodecCtx->thread_count = 2;
	pCodecCtx->flags2 |= AV_CODEC_FLAG2_FAST;
}

#else
pCodecCtx->opaque = nullptr;
pCodecCtx->thread_count = 2;
pCodecCtx->flags2 |= AV_CODEC_FLAG2_FAST;
#endif // USE_HWACCEL
if(avcodec_open2(pCodecCtx, pCodec,NULL)<0){
printf("Could not open codec.\n");
return -1;
}

screen_w = pCodecCtx->width;
screen_h = pCodecCtx->height;
AVPixelFormat image_transf_format = AV_PIX_FMT_NV12;

pFrame=av_frame_alloc();
sw_frame = av_frame_alloc();

pFrameTarget = av_frame_alloc();
out_buffer = (unsigned char *)av_malloc(av_image_get_buffer_size(image_transf_format, screen_w, screen_h, 1));
av_image_fill_arrays(pFrameTarget->data, pFrameTarget->linesize, out_buffer,
	image_transf_format, screen_w, screen_h, 1);
pFrameTarget->width = screen_w;
pFrameTarget->height = screen_h;
packet=(AVPacket *)av_malloc(sizeof(AVPacket));
//Output Info-----------------------------
printf("--------------- File Information ----------------\n");
av_dump_format(pFormatCtx,0,filepath,0);
printf("-------------------------------------------------\n");

if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {  
	printf( "Could not initialize SDL - %s\n", SDL_GetError()); 
	return -1;
} 

////SDL 2.0 Support for multiple windows
screen = SDL_CreateWindow("Simplest ffmpeg player's Window", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
	screen_w, screen_h,
	SDL_WINDOW_OPENGL);
sdlRenderer = SDL_CreateRenderer(screen, -1, 0);  
sdlTexture = SDL_CreateTexture(sdlRenderer, SDL_PIXELFORMAT_NV12, SDL_TEXTUREACCESS_STREAMING, screen_w, screen_h);

//SDL End----------------------
while(av_read_frame(pFormatCtx, packet)>=0){
	if(packet->stream_index==videoindex)
	{
		int nTime0 = GetTickCount();
		ret = avcodec_send_packet(pCodecCtx, packet);
		if(ret < 0)
			continue;
		ret = avcodec_receive_frame(pCodecCtx, pFrame);
		if(ret < 0){
			printf("Decode Error.\n");
			continue;
		}

		if (pFrame->format == AV_PIX_FMT_DXVA2_VLD)
		{
			InputStream* ist = (InputStream *)pCodecCtx->opaque;
			int nTime0 = GetTickCount();
			ist->hwaccel_retrieve_data(pCodecCtx, pFrame);
			//sw_frame = pFrame;
			av_frame_move_ref(sw_frame, pFrame);
			printf("convert time :%d\n", GetTickCount() - nTime0);
			//sw_frame = pFrame;
		}
		else
		{
			sw_frame = pFrame;
		}
		if(1){
			if (!img_convert_ctx)
			{
				img_convert_ctx = sws_getContext(sw_frame->width, sw_frame->height, (AVPixelFormat)sw_frame->format,
					pFrameTarget->width, pFrameTarget->height, image_transf_format, SWS_BICUBIC, NULL, NULL, NULL);
			}
			sws_scale(img_convert_ctx, (const uint8_t* const*)sw_frame->data, sw_frame->linesize, 0, sw_frame->height,
				pFrameTarget->data, pFrameTarget->linesize);

			SDL_UpdateTexture(sdlTexture, NULL, pFrameTarget->data[0], pFrameTarget->linesize[0]);
			SDL_RenderClear(sdlRenderer);
			SDL_RenderCopy(sdlRenderer, sdlTexture, NULL, NULL);
			SDL_RenderPresent(sdlRenderer);
		}
		SDL_Delay(40);
		av_frame_unref(sw_frame);
	}
}
sws_freeContext(img_convert_ctx);

SDL_Quit();

av_frame_free(&pFrameTarget);
av_frame_free(&pFrame);
avcodec_close(pCodecCtx);
avformat_close_input(&pFormatCtx);

return 0;

}

[aliakseis]

I've just tried your code:
https://github.com/aliakseis/SDL-example
Seems to be working fine with small changes so far. However the SDL frame transfer functionality does not seem to be efficient, probably some tweaking is required.

[aliakseis]

Sorry, made an update - there was an issue.
It seems to me that yv12 matches decoding needs better than nv12.

[w136111526]

Yes, yv12 is normal, thank you very much.

[w136111526]

Is the data after hard decoding is nv21? and I tried H. 265 video(HEVC format). Why not support hard decoding? I tried Win7 and Win10 and they weren't working, but not enough dxva2_mode.

[aliakseis]

Just made some updates for H.265 stuff, probably it is fixed now:
http://jell.yfish.us/

[aliakseis]

BTW here is a portable player prototype:
https://github.com/aliakseis/FFmpegPlayer/tree/master/QtPlayer