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58 int ret, fps, chunk_header;
114 avio_seek(pb, chunk_header - 3, SEEK_SET);
124 int ret, audio_offset, video_offset, chunk_size, audio_size = 0;
143 if (audio_offset < 0 || video_offset < audio_offset || chunk_size < video_offset) {
147 audio_size = video_offset - audio_offset;
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.
#define AVERROR_EOF
End of file.
#define AV_CHANNEL_LAYOUT_MONO
int ff_get_extradata(void *logctx, AVCodecParameters *par, AVIOContext *pb, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0 and f...
int64_t duration
Decoding: duration of the stream, in stream time base.
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
AVCodecParameters * codecpar
Codec parameters associated with this stream.
static int read_header(FFV1Context *f)
This structure contains the data a format has to probe a file.
AVChannelLayout ch_layout
Audio only.
int sample_rate
Audio only.
int64_t nb_frames
number of frames in this stream if known or 0
unsigned int avio_rl32(AVIOContext *s)
#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.
int avio_r8(AVIOContext *s)
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
int bits_per_coded_sample
The number of bits per sample in the codedwords.
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 AVERROR_INVALIDDATA
Invalid data found when processing input.
#define MKTAG(a, b, c, d)
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.