Hi,
I'm trying to build a basic program to read in a video and display it.
So far i'm blocked in the reading part. Here is the code and at the end
you will find the program output
/*
* streamvideo.c
*
* Created on: Jan 6, 2012
* Author:
*/
#include <stdlib.h>
#include <stdio.h>
#include <inttypes.h>
#include <stdio.h>
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <SFML/Graphics/RenderWindow.h>
#include <SFML/Audio.h>
#include <SFML/Graphics.h>
#define INBUF_SIZE 512
int main( int argc, char* argv[] )
{
sfWindowSettings Settings = {24, 8, 0};
sfVideoMode Mode = {800, 600, 32};
sfRenderWindow* App;
sfImage* Image;
sfSprite* Sprite;
sfFont* Font;
sfString* Text;
sfMusic* Music;
sfEvent Event;
AVFormatContext *pFormatCtx = NULL;
AVCodecContext *pCodecCtx = NULL;
AVCodec *pCodec = NULL;
AVPacket packet ;
AVFrame *pFrame;
AVFrame *pFrameYUV;
int iFrameSize;
struct SwsContext *img_convert_ctx;
int frameCount=0;
int frameFinished;
int i, numBytes;
uint8_t *buffer;
//char* input_filename = "rtsp://wm-live.sr.se/SR-P3-High/";
char* input_filename = "video.mpeg";
// Initialize the library by registering all file formats and codecs so
// they can be used automatically.
av_register_all();
avcodec_register_all();
//avformat_network_init();
printf("Registered file formats and codecs\n");
/*
* Getting ready to read the input.
*/
// Open the video file. The last three arguments to open() are
fileformat,
// buffer size, and format options, we let libavformat to select these.
printf("Input name: %s\n", input_filename);
if(avformat_open_input(&pFormatCtx, input_filename,NULL,NULL) != 0)
{
fprintf(stderr, "could not open input: %s!\n", input_filename);
return -1;
}
printf("opened input\n");
// Get stream information and dump it
if (avformat_find_stream_info(pFormatCtx,NULL) <0)
{
fprintf(stderr, "could not find stream information\n");
return -1;
}
av_dump_format(pFormatCtx, 0, input_filename, 0 );
printf("dump format done\n");
// Find the first video stream
int videoStream=-1;
for(i=0; i<pFormatCtx->nb_streams; i++)
if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO) {
printf("Found a video stream\n");
videoStream=i;
break;
}
if(videoStream==-1)
{
printf("Didn't find a video stream\n");
return -1; // Didn't find a video stream
}
// Get a pointer to the codec context for the video stream
pCodecCtx=pFormatCtx->streams[videoStream]->codec;
// Find the decoder for the video stream
pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
if(pCodec==NULL) {
fprintf(stderr, "Unsupported codec!\n");
return -1; // Codec not found
}
CodecCtx->height);
int height = pCodecCtx->height;
int width = pCodecCtx->width;
printf("video width: %d\n", pCodecCtx->width);
printf("video height: %d\n", pCodecCtx->height);
iFrameSize = pCodecCtx->width * pCodecCtx->height * 3;
pCodecCtx = avcodec_alloc_context3(pCodec);
// if(pCodec->capabilities & CODEC_CAP_TRUNCATED)
pCodecCtx->flags|=CODEC_FLAG_TRUNCATED;
printf("Frame size %d\n",iFrameSize);
// Open codec
if(avcodec_open2(pCodecCtx, pCodec,NULL)<0)
{
printf("Could not open Codec");
return -1; // Could not open codec
}
numBytes=avpicture_get_size(PIX_FMT_YUV420P, width, height);
//numBytes=avpicture_get_size(PIX_FMT_RGB24, pCodecCtx->width,
pCodecCtx->height);
buffer=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
avpicture_fill((AVPicture *)pFrameYUV, buffer, PIX_FMT_YUV420P,
pCodecCtx->width, pCodecCtx->height);
//One more thing left to do: Allocate a video frame to store the decoded
images in:
// Allocate video frame
pFrame=avcodec_alloc_frame();
// Allocate an AVFrame structure
pFrameYUV=avcodec_alloc_frame();
if(pFrameYUV==NULL)
return -1;
// Determine required buffer size and allocate buffer
numBytes=avpicture_get_size(PIX_FMT_YUV420P,
pCodecCtx->width, pCodecCtx->height);
buffer=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
avpicture_fill((AVPicture *)pFrameYUV, buffer,
PIX_FMT_YUV420P,
pCodecCtx->width, pCodecCtx->height);
// Data = new sf::Uint8[pCodecCtx->width *
pCodecCtx->height * 4];
printf("Done\n");
//end video initialization
/****************
* Display video *
*****************/
i=0;
int len =0;
while(av_read_frame(pFormatCtx, &packet)>=0) {
// Is this a packet from the video stream?
if(packet.stream_index==videoStream) {
// Decode video frame
//avcodec_decode_video2(pCodecCtx, pFrame,
&frameFinished,packet.data, packet.size);
//len = avcodec_decode_video2(pCodecCtx, pFrame,
pFrameRGB, &packet);
len = avcodec_decode_video2(pCodecCtx, pFrame,
&frameFinished, &packet);
// Convert the image from its native format to RGB
avpicture_fill((AVPicture *)pFrameYUV, buffer,
PIX_FMT_YUV420P,
pCodecCtx->width,
pCodecCtx->height);
printf("len:%d\n",len);
//sleep(1);
if (len < 0) {
fprintf(stderr, "Error while decoding\n");
}
}
}
return 0;
}
#Program execution
> ./videostreaming
Registered file formats and codecs
Input name: video.mpeg
opened input
[mpeg @ 0x9972040] max_analyze_duration 5000000 reached at 5000000
Input #0, mpeg, from 'video.mpeg':
Duration: 00:02:15.23, start: 1.000000, bitrate: 632 kb/s
Stream #0:0[0x1e0]: Video: mpeg1video, yuv420p, 640x360 [SAR 1:1
DAR 16:9], 104857 kb/s, 25 fps, 25 tbr, 90k tbn, 25 tbc
Stream #0:1[0x1c0]: Audio: mp2, 44100 Hz, stereo, s16, 128 kb/s
dump format done
Found a video stream
video width: 640
video height: 360
Frame size 691200
[IMGUTILS @ 0xbfd09a24] Picture size 0x0 is invalid
[IMGUTILS @ 0xbfd09a14] Picture size 0x0 is invalid
[IMGUTILS @ 0xbfd09a24] Picture size 0x0 is invalid
Done
len:3508
[mpeg1video @ 0x9cc45e0] Warning MVs not available
......
What is the Picture size message about ?? can you help me ?
thanks,
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