一句话：解码时，当AVCodecContext的refcounted_frames字段为0，则frame的分配与释放由ffmpeg内部本身控制。ide
那么使用是要注意不要破坏picture的数据指针。this
依据：spa
AVCodecContext
指针
/**
* If non-zero, the decoded audio and video frames returned from
* avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
* and are valid indefinitely. The caller must free them with
* av_frame_unref() when they are not needed anymore.
* Otherwise, the decoded frames must not be freed by the caller and are
* only valid until the next decode call.
*
* - encoding: unused
* - decoding: set by the caller before avcodec_open2().
*/
int refcounted_frames;
code
* @param[out] picture The AVFrame in which the decoded video frame will be stored.
* Use av_frame_alloc() to get an AVFrame. The codec will
* allocate memory for the actual bitmap by calling the
* AVCodecContext.get_buffer2() callback.
* When AVCodecContext.refcounted_frames is set to 1, the frame is
* reference counted and the returned reference belongs to the
* caller. The caller must release the frame using av_frame_unref()
* when the frame is no longer needed. The caller may safely write
* to the frame if av_frame_is_writable() returns 1.
* When AVCodecContext.refcounted_frames is set to 0, the returned
* reference belongs to the decoder and is valid only until the
* next call to this function or until closing or flushing the
* decoder. The caller may not write to it.
get
int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
int *got_picture_ptr,
const AVPacket *avpkt);