Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
enum AVMediaType codec_type
General type of the encoded data.
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
static int daud_header(AVFormatContext *s)
AVCodecParameters * codecpar
Codec parameters associated with this stream.
static int daud_packet(AVFormatContext *s, AVPacket *pkt)
AVChannelLayout ch_layout
Audio only.
int sample_rate
Audio only.
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
An AVChannelLayout holds information about the channel layout of audio data.
const AVInputFormat ff_daud_demuxer
int block_align
Audio only.
unsigned int avio_rb16(AVIOContext *s)
int bits_per_coded_sample
The number of bits per sample in the codedwords.
@ AV_CODEC_ID_PCM_S24DAUD
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
This structure stores compressed data.
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
#define MKTAG(a, b, c, d)
#define AV_CHANNEL_LAYOUT_5POINT1
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.