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44 (p->
buf[13] == 8 || p->
buf[13] == 16) &&
45 (p->
buf[15] & 2) != 0)
52 int64_t nb_samples, size_offset;
79 c->frame_size = 131072;
85 c->total_frames = (nb_samples +
c->frame_size - 1) /
c->frame_size;
86 c->last_frame_size = nb_samples %
c->frame_size;
88 for (
int i = 0;
i <
c->total_frames;
i++) {
98 size = size_offset - framepos;
144 pkt->
duration =
c->currentframe ==
c->total_frames ?
c->last_frame_size :
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
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
enum AVMediaType codec_type
General type of the encoded data.
This struct describes the properties of an encoded stream.
AVStream * avformat_new_stream(AVFormatContext *s, const struct AVCodec *c)
Add a new stream to a media file.
#define AVERROR_EOF
End of file.
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
int nb_channels
Number of channels in this layout.
int64_t ff_ape_parse_tag(AVFormatContext *s)
Read and parse an APE tag.
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...
int bits_per_raw_sample
This is the number of valid bits in each output sample.
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, int size, int distance, int flags)
Add an index entry into a sorted list.
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
int64_t duration
Decoding: duration of the stream, in stream time base.
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
int64_t timestamp
Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are...
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.
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
int sample_rate
Audio only.
unsigned int avio_rl32(AVIOContext *s)
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed.
#define i(width, name, range_min, range_max)
unsigned int avio_rl24(AVIOContext *s)
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
#define AVIO_SEEKABLE_NORMAL
Seeking works like for a local file.
AVIndexEntry * index_entries
Only used if the format does not support seeking natively.
static int read_probe(const AVProbeData *p)
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
This structure stores compressed data.
#define flags(name, subs,...)
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
#define MKTAG(a, b, c, d)
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base.
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.