任何人都可以帮助理解AVFrame.linesize []？ [英] Can anyone help in understanding AVFrame.linesize[]?

问题描述

我试图找到 AVFrame.linesize [] 的每个单元格，但是我没有找到。

I tried to find what each cell of AVFrame.linesize[] means, but I didn't found.

据了解， linesize [0] 是宽度， linesize [1] / code>是高度。

As I understood linesize[0] is the width, linesize[1] is the height.

1. 如果我是对的其他单元格意味着什么？


2. 为什么 avcodec_decode_video2（codecCtxDecode，frameDecoded，& frameFinished，& packet）; only linesize [0]具有值，其他单元格始终为0？

1. If I'm right what does other cells mean?
2. why after avcodec_decode_video2(codecCtxDecode, frameDecoded, &frameFinished, &packet); only linesize[0] has the value and other cells are always 0?

UPDATED

我认为AVFrame.data [i]和AVFrame.linesize [i]是行中特定颜色的数据和行的长度，我是否正确？

I think AVFrame.data[i] and AVFrame.linesize[i] are the data of specific color in the row and the length of the row, am I correct?

推荐答案

在平面的情况下数据，例如 YUV420 ， linesize [i] 包含 i -th plane。

In the case of planar data, such as YUV420, linesize[i] contains stride for the i-th plane.

例如，对于框架 640x480 data [ 0] 包含指向 Y 组件的指针，数据[1] 和 data [2] 包含指向 U 和 V 飞机的指针。在这种情况下， linesize [0] == 640 ， linesize [1] == linesize [2] == 320 （因为 U 和 V 飞机小于 Y 平面一半）

For example, for frame 640x480 data[0] contains pointer to Y component, data[1] and data[2] contains pointers to U and V planes. In this case, linesize[0] == 640, linesize[1] == linesize[2] == 320 (because the U and V planes is less than Y plane half)

在像素数据（ RGB24 ）的情况下，只有一个飞机（ data [0] ）和 linesize [0] == width * channels （ 640 * 3 RGB24 ）

In the case of pixel data (RGB24), there is only one plane (data[0]) and linesize[0] == width * channels (640 * 3 for RGB24)

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