Determining size of data[0] in AVFrame of FFMPEG

Question

I am trying to allocate AVFrame->data[0] of a video frame to uint8_t* buffer using the following lines of code :

size_t sizeOfFrameData = mpAVFrameInput->linesize[0] * mpAVFrameInput->height;
        
memcpy(mFrameData, mpAVFrameInput->data[0], sizeOfFrameData);

I would like to know if this is a correct way of copying frame data to uint8_t* variable in FFMPEG?

Did you try if it works (i.e. compiles and you get expected output)? — 463035818_is_not_an_ai, Mar 27 '15 at 10:34
Although the program is being compiled but not getting expected output — , Mar 27 '15 at 10:50
Then most likely this is not the correct way (supposed there are not other bugs in your code). — 463035818_is_not_an_ai, Mar 27 '15 at 10:51
That is correct for non-planar formats. For planar formats (like YUV) you need to do the same for the other planes. — szatmary, Mar 27 '15 at 15:17

aergistal · Accepted Answer · 2015-03-27T12:58:05.077

3

To get the buffer size:

int avpicture_get_size(enum AVPixelFormat pix_fmt, int width, int height);

To copy pixel data:

int avpicture_layout(const AVPicture *src, enum AVPixelFormat pix_fmt,
                     int width, int height,
                     unsigned char *dest, int dest_size);

edited Mar 27 '15 at 12:58

answered Mar 27 '15 at 12:41

aergistal

29,947
5
70
92

score 1 · Answer 2 · edited Jul 20 '20 at 19:46

Given avpicture_get_size() is deprecated , this is possible with:

int numBytes = av_image_get_buffer_size(
    enum AVPixelFormat
    int width,
    int height,
    int align
    );

note that for align value of 32 is usually used , I have seen posts using 1 bit might cause distortion on the frame;

Its possible however to fill frame buffer data (i.e without size information) with :

int av_image_fill_arrays(uint8_t *dst_data[4], int dst_linesize[4],
                         const uint8_t *src,
                         enum AVPixelFormat pix_fmt, int width, int height, int align);

score 0 · Answer 3 · edited Feb 04 '22 at 23:02

The avpicture_* API is now deprecated. Instead, use av_image_fill_plane_sizes to get each plane's size (the size of data[0] array).

int av_image_fill_plane_sizes   (
size_t  size[4],
enum AVPixelFormat  pix_fmt,
int     height,
const ptrdiff_t     linesizes[4] 
)

Note that the linesizes should be converted to ptrdiff_t (long long*) first.

You can find more here: https://www.ffmpeg.org/doxygen/trunk/group__lavu__picture.html

Determining size of data[0] in AVFrame of FFMPEG

3 Answers3