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How to Convert NV12 to BGR(AVFrame to cv::Mat)
1
I decoded videoframe by using FFMPEG Library from IP Camera.
This videoframe format is AV_PIX_FMT_NV12. AV_PIX_FMT_NV12 is defined on FFMPEG Library.
I want to convert NV12 to BGR (AVFrame to cv::Mat), so I try to do this
but I got wrong image:
Please help me. I want to convert properly. Can anyone guess this problem?
Please refer to following code:
void CALLBACK MyCallbackFunc(AVFrame *avFrame )
{
if (avFrame != NULL)
{
cv::Mat imageRGB;
cv::Mat picI420 = cv::Mat(avFrame->height * 3 / 2, avFrame->width, CV_8UC1, avFrame->data[0]);
cv::cvtColor(picI420, imageRGB, CV_YUV2BGR_NV12);
imshow("imageRGB", imageRGB);
cvWaitKey(1);
}
}
Sorry for my bad english. If you want more information please comment below.
opencv ffmpeg mat yuv
edited Jan 1 at 10:49
Brian Tompsett - 汤莱恩
4,2321338102
asked Jan 1 at 10:30
Steven.YeunSteven.Yeun
62
add a comment |
1
I decoded videoframe by using FFMPEG Library from IP Camera.
This videoframe format is AV_PIX_FMT_NV12. AV_PIX_FMT_NV12 is defined on FFMPEG Library.
I want to convert NV12 to BGR (AVFrame to cv::Mat), so I try to do this
but I got wrong image:
Please help me. I want to convert properly. Can anyone guess this problem?
Please refer to following code:
void CALLBACK MyCallbackFunc(AVFrame *avFrame )
{
if (avFrame != NULL)
{
cv::Mat imageRGB;
cv::Mat picI420 = cv::Mat(avFrame->height * 3 / 2, avFrame->width, CV_8UC1, avFrame->data[0]);
cv::cvtColor(picI420, imageRGB, CV_YUV2BGR_NV12);
imshow("imageRGB", imageRGB);
cvWaitKey(1);
}
}
Sorry for my bad english. If you want more information please comment below.
opencv ffmpeg mat yuv
edited Jan 1 at 10:49
Brian Tompsett - 汤莱恩
4,2321338102
asked Jan 1 at 10:30
Steven.YeunSteven.Yeun
62
1
Adding a sample frame of data with its dimensions might help you to get an answer.
– Mark Setchell
Jan 1 at 12:19
Maybe it is not the cause of your issue but I see two let say 'mistake'. 1) You send and mono channel image to cvtColor. 2) If I well understand avFrame->data store the data columnwise. I deduct that from the fact that you divide the height by the number of channels. It is to know that Mat container expect data ordered rowwise and interleaved. e.g. let suppose a matrix of 3 rows and 4 columns BGR using unsigned char data a Mat object store the informations as: [row0_column0_blue, row0_column0_green, row0_column0_red, row0_column1_blue,..., row3_column4_red]. Hope it helps.
– John_Sharp1318
Jan 1 at 20:24
add a comment |
1
1
1
I decoded videoframe by using FFMPEG Library from IP Camera.
This videoframe format is AV_PIX_FMT_NV12. AV_PIX_FMT_NV12 is defined on FFMPEG Library.
I want to convert NV12 to BGR (AVFrame to cv::Mat), so I try to do this
but I got wrong image:
Please help me. I want to convert properly. Can anyone guess this problem?
Please refer to following code:
void CALLBACK MyCallbackFunc(AVFrame *avFrame )
{
if (avFrame != NULL)
{
cv::Mat imageRGB;
cv::Mat picI420 = cv::Mat(avFrame->height * 3 / 2, avFrame->width, CV_8UC1, avFrame->data[0]);
cv::cvtColor(picI420, imageRGB, CV_YUV2BGR_NV12);
imshow("imageRGB", imageRGB);
cvWaitKey(1);
}
}
Sorry for my bad english. If you want more information please comment below.
opencv ffmpeg mat yuv
edited Jan 1 at 10:49
Brian Tompsett - 汤莱恩
4,2321338102
asked Jan 1 at 10:30
Steven.YeunSteven.Yeun
62
I decoded videoframe by using FFMPEG Library from IP Camera.
This videoframe format is AV_PIX_FMT_NV12. AV_PIX_FMT_NV12 is defined on FFMPEG Library.
I want to convert NV12 to BGR (AVFrame to cv::Mat), so I try to do this
but I got wrong image:
Please help me. I want to convert properly. Can anyone guess this problem?
Please refer to following code:
void CALLBACK MyCallbackFunc(AVFrame *avFrame )
{
if (avFrame != NULL)
{
cv::Mat imageRGB;
cv::Mat picI420 = cv::Mat(avFrame->height * 3 / 2, avFrame->width, CV_8UC1, avFrame->data[0]);
cv::cvtColor(picI420, imageRGB, CV_YUV2BGR_NV12);
imshow("imageRGB", imageRGB);
cvWaitKey(1);
}
}
Sorry for my bad english. If you want more information please comment below.
opencv ffmpeg mat yuv
opencv ffmpeg mat yuv
edited Jan 1 at 10:49
Brian Tompsett - 汤莱恩
4,2321338102
asked Jan 1 at 10:30
Steven.YeunSteven.Yeun
62
edited Jan 1 at 10:49
Brian Tompsett - 汤莱恩
4,2321338102
asked Jan 1 at 10:30
Steven.YeunSteven.Yeun
62
edited Jan 1 at 10:49
Brian Tompsett - 汤莱恩
4,2321338102
edited Jan 1 at 10:49
Brian Tompsett - 汤莱恩
4,2321338102
edited Jan 1 at 10:49
Brian Tompsett - 汤莱恩
4,2321338102
4,2321338102
asked Jan 1 at 10:30
Steven.YeunSteven.Yeun
62
asked Jan 1 at 10:30
Steven.YeunSteven.Yeun
62
asked Jan 1 at 10:30
Steven.YeunSteven.Yeun
62
62
1
Adding a sample frame of data with its dimensions might help you to get an answer.
– Mark Setchell
Jan 1 at 12:19
Maybe it is not the cause of your issue but I see two let say 'mistake'. 1) You send and mono channel image to cvtColor. 2) If I well understand avFrame->data store the data columnwise. I deduct that from the fact that you divide the height by the number of channels. It is to know that Mat container expect data ordered rowwise and interleaved. e.g. let suppose a matrix of 3 rows and 4 columns BGR using unsigned char data a Mat object store the informations as: [row0_column0_blue, row0_column0_green, row0_column0_red, row0_column1_blue,..., row3_column4_red]. Hope it helps.
– John_Sharp1318
Jan 1 at 20:24
add a comment |
1
Adding a sample frame of data with its dimensions might help you to get an answer.
– Mark Setchell
Jan 1 at 12:19
Maybe it is not the cause of your issue but I see two let say 'mistake'. 1) You send and mono channel image to cvtColor. 2) If I well understand avFrame->data store the data columnwise. I deduct that from the fact that you divide the height by the number of channels. It is to know that Mat container expect data ordered rowwise and interleaved. e.g. let suppose a matrix of 3 rows and 4 columns BGR using unsigned char data a Mat object store the informations as: [row0_column0_blue, row0_column0_green, row0_column0_red, row0_column1_blue,..., row3_column4_red]. Hope it helps.
– John_Sharp1318
Jan 1 at 20:24
1
1
Adding a sample frame of data with its dimensions might help you to get an answer.
– Mark Setchell
Jan 1 at 12:19
Adding a sample frame of data with its dimensions might help you to get an answer.
– Mark Setchell
Jan 1 at 12:19
Maybe it is not the cause of your issue but I see two let say 'mistake'. 1) You send and mono channel image to cvtColor. 2) If I well understand avFrame->data store the data columnwise. I deduct that from the fact that you divide the height by the number of channels. It is to know that Mat container expect data ordered rowwise and interleaved. e.g. let suppose a matrix of 3 rows and 4 columns BGR using unsigned char data a Mat object store the informations as: [row0_column0_blue, row0_column0_green, row0_column0_red, row0_column1_blue,..., row3_column4_red]. Hope it helps.
– John_Sharp1318
Jan 1 at 20:24
Maybe it is not the cause of your issue but I see two let say 'mistake'. 1) You send and mono channel image to cvtColor. 2) If I well understand avFrame->data store the data columnwise. I deduct that from the fact that you divide the height by the number of channels. It is to know that Mat container expect data ordered rowwise and interleaved. e.g. let suppose a matrix of 3 rows and 4 columns BGR using unsigned char data a Mat object store the informations as: [row0_column0_blue, row0_column0_green, row0_column0_red, row0_column1_blue,..., row3_column4_red]. Hope it helps.
– John_Sharp1318
Jan 1 at 20:24
add a comment |
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1
Adding a sample frame of data with its dimensions might help you to get an answer.
– Mark Setchell
Jan 1 at 12:19
Maybe it is not the cause of your issue but I see two let say 'mistake'. 1) You send and mono channel image to cvtColor. 2) If I well understand avFrame->data store the data columnwise. I deduct that from the fact that you divide the height by the number of channels. It is to know that Mat container expect data ordered rowwise and interleaved. e.g. let suppose a matrix of 3 rows and 4 columns BGR using unsigned char data a Mat object store the informations as: [row0_column0_blue, row0_column0_green, row0_column0_red, row0_column1_blue,..., row3_column4_red]. Hope it helps.
– John_Sharp1318
Jan 1 at 20:24