I have an array that keeps which frames are the keyframe and I want to
create a video with these keyframes but first off all I try to save
these keyframes in a directory in sdcard called "keyframes".
I use a video that I have 217 keyframe and I think I understand using
of av_seek_frame() wrong .
Because my code always save the last frame 217 times with different
names like frame1,frame2...frame217.
Can someone help me? Thank you.
void SaveFrame(AVFrame *pFrame, int width, int height, int iFrame) {
log_message("saving frame.");
FILE *pFile;
char szFilename[32];
int y;
// Open file
sprintf(szFilename, "/sdcard/keyframes/frame%d.ppm", iFrame+1);
pFile=fopen(szFilename, "wb");
if(pFile==NULL)
return;
// Write header
fprintf(pFile, "P6\n%d %d\n255\n", width, height);
// Write pixel data
for(y=0; y<height; y++)
fwrite(pFrame->data[0]+y*pFrame->linesize[0], 1, width*3, pFile);
// Close file
fclose(pFile);
}
jint Java_com_test_Test_takePics(JNIEnv* env, jobject javaThis) {
const char path[256] = "/sdcard/keyframes/";
if (mkdir (path) != 0) printf("Fail Retry");
log_message("Fonka girdim!\n");
AVFormatContext *pFormatCtx;
int i, videoStream, j;
AVCodecContext *pCodecCtx;
AVCodec *pCodec;
AVFrame *pFrame;
AVFrame *pFrameRGB;
AVPacket packet;
int frameFinished;
int numBytes;
uint8_t *buffer;
unsigned char r, g, b;
int framecount;
char* filename = "/sdcard/do-beer-not-drugs.3gp";
// Register all formats and codecs
av_register_all();
// Open video file
if(av_open_input_file(&pFormatCtx, filename, NULL, 0, NULL)!=0)
return -1; // Couldn't open file
// Retrieve stream information
if(av_find_stream_info(pFormatCtx)<0)
return -1; // Couldn't find stream information
// Dump information about file onto standard error
dump_format(pFormatCtx, 0, filename, 0);
framecount = pFormatCtx->streams[0]->nb_frames;
hist = malloc(framecount*sizeof(int*));
for (j = 0; j < framecount; ++j) {
hist[j] = malloc(sizeof(int)*64); // this is because we
use 64-bin
histogram
}
for (i = 0; i < framecount; i++) {
for (j = 0; j < 64; j++) {
hist[i][j] = 0;
}
}
// Find the first video stream
videoStream=-1;
for(i=0; i<pFormatCtx->nb_streams; i++)
if(pFormatCtx->streams[i]->codec-
>codec_type==CODEC_TYPE_VIDEO)
{
videoStream=i;
break;
}
if(videoStream==-1)
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)
return -1; // Codec not found
// Open codec
if(avcodec_open(pCodecCtx, pCodec)<0)
return -1; // Could not open codec
// Hack to correct wrong frame rates that seem to be generated by
some codecs
if(pCodecCtx->time_base.num>1000 && pCodecCtx->time_base.den==1)
pCodecCtx->time_base.den=1000;
// Allocate video frame
pFrame=avcodec_alloc_frame();
// Allocate an AVFrame structure
pFrameRGB=avcodec_alloc_frame();
if(pFrameRGB==NULL)
return -1;
// Determine required buffer size and allocate buffer
numBytes=avpicture_get_size(PIX_FMT_RGB24, pCodecCtx->width,
pCodecCtx->height);
buffer=malloc(numBytes);
// Assign appropriate parts of buffer to image planes in pFrameRGB
avpicture_fill((AVPicture *)pFrameRGB, buffer, PIX_FMT_RGB24,
pCodecCtx->width, pCodecCtx->height);
// Read frames and save first five frames to disk
i=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);
// Did we get a video frame?
if(frameFinished)
{
static struct SwsContext *img_convert_ctx;
// Convert the image into YUV format that SDL
uses
if(img_convert_ctx == NULL) {
int w = pCodecCtx->width;
int h = pCodecCtx->height;
img_convert_ctx = sws_getContext(w, h,
pCodecCtx->pix_fmt,
w, h,
PIX_FMT_RGB24, SWS_BICUBIC,
NULL,
NULL, NULL);
if(img_convert_ctx == NULL) {
fprintf(stderr, "Cannot
initialize the conversion context!\n");
exit(1);
}
}
int ret = sws_scale(img_convert_ctx,
pFrame->data, pFrame-
>linesize, 0,
pCodecCtx->height,
pFrameRGB->data, pFrameRGB->linesize);
for (j = 0; j <
3*pCodecCtx->height*pCodecCtx->width -3; j++) {
r = (unsigned char) pFrameRGB->data[0][j];
g = (unsigned char) pFrameRGB->data[0][j
+1];
b = (unsigned char) pFrameRGB->data[0][j
+2];
r = (unsigned char) ((r >> 2) & 0x30);
g = (unsigned char) ((g >> 4) & 0x0C);
b = (unsigned char) ((b >> 6) & 0x03);
unsigned char h = (unsigned char)(r|g|b);
hist[i][h]++;
}
i++;
}
}
// Free the packet that was allocated by av_read_frame
av_free_packet(&packet);
}
framecount = i;
int keyframelength=select_keyFrames(framecount);
for(i=1;i<keyframelength+1;i++){
int64_t timeStamp = (int64_t)((pFormatCtx->duration) /
framecount)*keyFrames[i]/100;
av_seek_frame(pFormatCtx,0,timeStamp,AVSEEK_FLAG_ANY);
SaveFrame(pFrameRGB, pCodecCtx->width, pCodecCtx->height, i);
}
free(keyFrames);
// Free the RGB image
free(buffer);
av_free(pFrameRGB);
// Free the YUV frame
av_free(pFrame);
// Close the codec
avcodec_close(pCodecCtx);
// Close the video file
av_close_input_file(pFormatCtx);
return 0;
}
--
You received this message because you are subscribed to the Google
Groups "Android Developers" group.
To post to this group, send email to android-developers@googlegroups.com
To unsubscribe from this group, send email to
android-developers+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/android-developers?hl=en
