前段时间实现了利用三星S3C6410一边压缩视频生成H264文件一边抓取并压缩生成jpg图片。核心步骤如下:
/* Codec set */
/* Get capability */
ret = ioctl(cam_c_fp , VIDIOC_QUERYCAP, &cap);
一边压缩视频:
if(frame_count == 1)
encoded_buf = mfc_encoder_exe(handle, g_yuv, YUV_FRAME_BUFFER_SIZE, 1, &encoded_size);
else
encoded_buf = mfc_encoder_exe(handle, g_yuv, YUV_FRAME_BUFFER_SIZE, 0, &encoded_size);
2.一边获取视频中的某一帧的数据:
if (read(cam_c_fp, g_yuv_cc, g_YUV420_Frame_Buffer_Size) < 0) {
perror("read()");}
3.读取完数据之后,因为图片压缩前的格式必须是yuv422的,而摄像头的数据格式为yuv420所以需要转化:
convert_yuv420p_to_yuv422_my( g_yuv_cc,g_yuv_c,g_codec_Width,g_codec_Height);
转化的具体实现为:
//平面YUV420转平面YUV422
static void convert_yuv420p_to_yuv422_my(unsigned char *src,unsigned char *dst,int width,int height)
{
int i,j;
unsigned char *pY420_0=src;
unsigned char *pY420_1=src+width;
unsigned char *pU420=src+width*height;
unsigned char *pV420=src+width*height*5/4;
unsigned char *pY422_0=dst;
unsigned char *pY422_1=dst+width*2;
for(i=0;i<height/2;i++)
{
for(j=0;j<width*2;j+=4)
{
*pY422_0++=*pY420_0++;
*pY422_1++=*pY420_1++;
*pY422_0++=*pU420;
*pY422_1++=*pU420++;
*pY422_0++=*pY420_0++;
*pY422_1++=*pY420_1++;
*pY422_0++=*pV420;
*pY422_1++=*pV420++;
}
pY420_0+=width;
pY420_1+=width;
pY422_0+=width*2;
pY422_1+=width*2;
}
}
4.转换完成之后就是简单的压缩过程了:
/* JPEG encoding */
/* JPEG Handle initialization */
jpg_handle = SsbSipJPEGEncodeInit();
if (jpg_handle < 0)
return;
/* Set encoding configs */
if((ret = SsbSipJPEGSetConfig(JPEG_SET_SAMPING_MODE, JPG_422)) != JPEG_OK)
return;
if((ret = SsbSipJPEGSetConfig(JPEG_SET_ENCODE_WIDTH, g_codec_Width)) != JPEG_OK)
return;
if((ret = SsbSipJPEGSetConfig(JPEG_SET_ENCODE_HEIGHT, g_codec_Height)) != JPEG_OK)
return;
if((ret = SsbSipJPEGSetConfig(JPEG_SET_ENCODE_QUALITY, JPG_QUALITY_LEVEL_2)) != JPEG_OK)
return;
if((ret = SsbSipJPEGSetConfig(JPEG_SET_ENCODE_THUMBNAIL, TRUE)) != JPEG_OK)
return;
//if((ret = SsbSipJPEGSetConfig(JPEG_SET_THUMBNAIL_WIDTH, 160)) != JPEG_OK)
// return;
// Main JPEG have to be multiple of Thumbnail resolution
if((ret = SsbSipJPEGSetConfig(JPEG_SET_THUMBNAIL_WIDTH, g_Thumbnail_Width)) != JPEG_OK)
return;
//if((ret = SsbSipJPEGSetConfig(JPEG_SET_THUMBNAIL_HEIGHT, 120)) != JPEG_OK)
//return;
// Main JPEG have to be multiple of Thumbnail resolution
if((ret = SsbSipJPEGSetConfig(JPEG_SET_THUMBNAIL_HEIGHT, g_Thumbnail_Height)) != JPEG_OK)
return;
/* Get input buffer address */
in_buf = SsbSipJPEGGetEncodeInBuf(jpg_handle, g_YUV422_Frame_Buffer_Size);
if(in_buf == NULL)
return;
/* Copy YUV data from camera to JPEG driver */
memcpy(in_buf, g_yuv_c, g_YUV422_Frame_Buffer_Size);
/* Make Exif info parameters */
memset(&ExifInfo, 0x00, sizeof(ExifFileInfo));
makeExifParam(&ExifInfo);
/* Encode YUV stream */
ret = SsbSipJPEGEncodeExe(jpg_handle, &ExifInfo, JPEG_USE_HW_SCALER); //with Exif
/* Get output buffer address */
out_buf = SsbSipJPEGGetEncodeOutBuf(jpg_handle, &jpg_size);
if(out_buf == NULL)
return;
fwrite(out_buf, 1, jpg_size, jpg_fp);
fclose(jpg_fp);
SsbSipJPEGEncodeDeInit(jpg_handle);
printf("CAPTURE SUCCESS\n");
原文地址:http://blog.csdn.net/ganxiang2011/article/details/45501281