Initialize the AVCodecContext to use the given AVCodec. Prior to using this
function the context has to be allocated with avcodec_alloc_context3().
The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
retrieving a codec.
@warning This function is not thread safe!
@note Always call this function before using decoding routines (such as
@ref avcodec_receive_frame()).
if (avcodec_open2(context, codec, opts) < 0)
exit(1);
@endcode
@param avctx The context to initialize.
@param codec The codec to open this context for. If a non-NULL codec has been
previously passed to avcodec_alloc_context3() or
for this context, then this parameter MUST be either NULL or
equal to the previously passed codec.
@param options A dictionary filled with AVCodecContext and codec-private options.
On return this object will be filled with options that were not found.
@return zero on success, a negative value on error
@see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
av_dict_set(), av_opt_find().
Initialize the AVCodecContext to use the given AVCodec. Prior to using this function the context has to be allocated with avcodec_alloc_context3().
The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(), avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for retrieving a codec.
@warning This function is not thread safe!
@note Always call this function before using decoding routines (such as @ref avcodec_receive_frame()).
@code avcodec_register_all(); av_dict_set(&opts, "b", "2.5M", 0); codec = avcodec_find_decoder(AV_CODEC_ID_H264); if (!codec) exit(1);
context = avcodec_alloc_context3(codec);
if (avcodec_open2(context, codec, opts) < 0) exit(1); @endcode
@param avctx The context to initialize. @param codec The codec to open this context for. If a non-NULL codec has been previously passed to avcodec_alloc_context3() or for this context, then this parameter MUST be either NULL or equal to the previously passed codec. @param options A dictionary filled with AVCodecContext and codec-private options. On return this object will be filled with options that were not found.
@return zero on success, a negative value on error @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(), av_dict_set(), av_opt_find().