Open an input stream and read the header. The codecs are not opened.
The stream must be closed with avformat_close_input().
@param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
May be a pointer to NULL, in which case an AVFormatContext is allocated by this
function and written into ps.
Note that a user-supplied AVFormatContext will be freed on failure.
@param url URL of the stream to open.
@param fmt If non-NULL, this parameter forces a specific input format.
Otherwise the format is autodetected.
@param options A dictionary filled with AVFormatContext and demuxer-private options.
On return this parameter will be destroyed and replaced with a dict containing
options that were not found. May be NULL.
@return 0 on success, a negative AVERROR on failure.
@note If you want to use custom IO, preallocate the format context and set its pb field.
Open an input stream and read the header. The codecs are not opened. The stream must be closed with avformat_close_input().
@param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context). May be a pointer to NULL, in which case an AVFormatContext is allocated by this function and written into ps. Note that a user-supplied AVFormatContext will be freed on failure. @param url URL of the stream to open. @param fmt If non-NULL, this parameter forces a specific input format. Otherwise the format is autodetected. @param options A dictionary filled with AVFormatContext and demuxer-private options. On return this parameter will be destroyed and replaced with a dict containing options that were not found. May be NULL.
@return 0 on success, a negative AVERROR on failure.
@note If you want to use custom IO, preallocate the format context and set its pb field.