48 #include <alsa/asoundlib.h> 106 snd_pcm_sframes_t delay = 0;
113 if (res == -EAGAIN) {
129 snd_pcm_delay(s->
h, &delay);
167 .priv_class = &alsa_demuxer_class,
#define LIBAVUTIL_VERSION_INT
void ff_timefilter_reset(TimeFilter *self)
Reset the filter.
static int audio_read_packet(AVFormatContext *s1, AVPacket *pkt)
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
const char * av_default_item_name(void *ptr)
Return the context name.
int frame_size
Audio only.
ALSA input and output: definitions and structures.
static const AVOption options[]
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
static av_cold int read_close(AVFormatContext *ctx)
Main libavdevice API header.
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
AVCodecID
Identify the syntax and semantics of the bitstream.
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
enum AVMediaType codec_type
General type of the encoded data.
common internal API header
int64_t av_rescale(int64_t a, int64_t b, int64_t c)
Rescale a 64-bit integer with rounding to nearest.
enum AVCodecID audio_codec_id
Forced audio codec_id.
static int audio_get_device_list(AVFormatContext *h, AVDeviceInfoList *device_list)
int channels
number of channels set by user
static int read_header(FFV1Context *f)
int64_t av_gettime(void)
Get the current time in microseconds.
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
TimeFilter * ff_timefilter_new(double time_base, double period, double bandwidth)
Create a new Delay Locked Loop time filter.
int ff_alsa_xrun_recover(AVFormatContext *s1, int err)
Try to recover from ALSA buffer underrun.
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
av_cold int ff_alsa_close(AVFormatContext *s1)
Close the ALSA PCM.
Describe the class of an AVClass context structure.
int ff_alsa_get_device_list(AVDeviceInfoList *device_list, snd_pcm_stream_t stream_type)
#define AV_OPT_FLAG_DECODING_PARAM
a generic parameter which can be set by the user for demuxing or decoding
#define flags(name, subs,...)
int period_size
preferred size for reads and writes, in frames
int sample_rate
Audio only.
double ff_timefilter_update(TimeFilter *self, double system_time, double period)
Update the filter.
void * priv_data
Format private data.
static av_cold int audio_read_header(AVFormatContext *s1)
int frame_size
bytes per sample * channels
int sample_rate
sample rate set by user
AVCodecParameters * codecpar
Codec parameters associated with this stream.
static const AVClass alsa_demuxer_class
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
AVInputFormat ff_alsa_demuxer
This structure stores compressed data.
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
av_cold int ff_alsa_open(AVFormatContext *ctx, snd_pcm_stream_t mode, unsigned int *sample_rate, int channels, enum AVCodecID *codec_id)
Open an ALSA PCM.