Allocate the stream private data and write the stream header to
an output media file.
@param s Media file handle, must be allocated with avformat_alloc_context().
Its oformat field must be set to the desired output format;
Its pb field must be set to an already opened AVIOContext.
@param options An AVDictionary filled with AVFormatContext and muxer-private options.
On return this parameter will be destroyed and replaced with a dict containing
options that were not found. May be NULL.
@return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec had not already been fully initialized in avformat_init,
AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec had already been fully initialized in avformat_init,
negative AVERROR on failure.
Allocate the stream private data and write the stream header to an output media file.
@param s Media file handle, must be allocated with avformat_alloc_context(). Its oformat field must be set to the desired output format; Its pb field must be set to an already opened AVIOContext. @param options An AVDictionary filled with AVFormatContext and muxer-private options. On return this parameter will be destroyed and replaced with a dict containing options that were not found. May be NULL.
@return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec had not already been fully initialized in avformat_init, AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec had already been fully initialized in avformat_init, negative AVERROR on failure.
@see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output.