与MediaExtractor问题

问题描述

我想获得在特定的时间特定的帧作为使用来自电影图像 MediaExtractor 和媒体codeC 。我能成功地做到这一点，如果：

I am trying to get specific frames at specific times as images from a movie using MediaExtractor and MediaCodec. I can do it successfully if:

• 我用 extractor.seekTo（时间，MediaExtractor.SEEK_TO_ preVIOUS_SYNC）; ，然而，这只是给最近的同步帧而不是目标帧
• 在我按顺序使用 extractor.advance（）提取所有的帧; ，但我需要得到目标帧不是所有
。

• I use extractor.seekTo(time, MediaExtractor.SEEK_TO_PREVIOUS_SYNC); , however, this only gives the nearest sync frame not the target frame.
• I sequentially extract all frames using extractor.advance(); , but I need to get the target frame not all.

于是，我尝试以下方法：

So, I try the following:

extractor.seekTo(time, MediaExtractor.SEEK_TO_PREVIOUS_SYNC);
while(extractor.getSampleTime()<time /*target time*/) extractor.advance();

此提供了正确的帧，但由于某些原因图像损坏。它看起来像正确的图像（一个我从成功案例获得），但与一些像素化和陌生的阴霾。

This provides the correct frame, but for some reason the image is corrupted. It looks like the correct image (the one I get from the successful cases), but with some pixelation and a strange haze.

在 while循环是成功的案例和破坏的人之间不同的唯一的事。怎样做才能推进 MediaExtractor 到一个特定的时间（不只是同步时间）没有得到损坏的图像？

The while-loop is the only thing that is different between the successful cases and the corrupted ones. What to do to advance MediaExtractor to a specific time (not just sync time) without getting a corrupted image?

推荐答案

由于法登的评论，我必须保持喂EN codeR因为 I帧有充分的画面和 P 和 B 帧有分歧（这是怎样的COM pression实现）。所以，我要开始与 I帧（这是一样的同步帧），并再喂另一帧去codeR接收完整的图像。

Thanks to fadden comment, I have to keep feeding the encoder since the I-frame has the full picture and the P and B frames have differences (this is how compression is achieved). So I need to start with an I-frame (it was same as sync frame) and keep feeding the other frames to the decoder to receive the full image.

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