lavf: clarify the lifetime of demuxed packets.

This commit is contained in:
Anton Khirnov 2012-10-31 19:59:53 +01:00
parent c8977f6d26
commit 717a450993
1 changed files with 16 additions and 10 deletions

View File

@ -158,9 +158,15 @@
* information will be in AVStream.time_base units, i.e. it has to be
* multiplied by the timebase to convert them to seconds.
*
* The packet data belongs to the demuxer and is invalid after the next call to
* av_read_frame(). The user must free the packet with av_free_packet() before
* calling av_read_frame() again or closing the file.
* If AVPacket.destruct is set on the returned packet, then the packet is
* allocated dynamically and the user may keep it indefinitely.
* Otherwise, if AVPacket.destruct is NULL, the packet data is backed by a
* static storage somewhere inside the demuxer and the packet is only valid
* until the next av_read_frame() call or closing the file. If the caller
* requires a longer lifetime, av_dup_packet() will make an av_malloc()ed copy
* of it.
* In both cases, the packet must be freed with av_free_packet() when it is no
* longer needed.
*
* @section lavf_decoding_seek Seeking
* @}
@ -1307,13 +1313,13 @@ int av_read_packet(AVFormatContext *s, AVPacket *pkt);
* omit invalid data between valid frames so as to give the decoder the maximum
* information possible for decoding.
*
* The returned packet is valid
* until the next av_read_frame() or until av_close_input_file() and
* must be freed with av_free_packet. For video, the packet contains
* exactly one frame. For audio, it contains an integer number of
* frames if each frame has a known fixed size (e.g. PCM or ADPCM
* data). If the audio frames have a variable size (e.g. MPEG audio),
* then it contains one frame.
* If pkt->destruct is NULL, then the packet is valid until the next
* av_read_frame() or until av_close_input_file(). Otherwise the packet is valid
* indefinitely. In both cases the packet must be freed with
* av_free_packet when it is no longer needed. For video, the packet contains
* exactly one frame. For audio, it contains an integer number of frames if each
* frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames
* have a variable size (e.g. MPEG audio), then it contains one frame.
*
* pkt->pts, pkt->dts and pkt->duration are always set to correct
* values in AVStream.time_base units (and guessed if the format cannot