40 static const char *
filter_descr =
"aresample=8000,aformat=sample_fmts=s16:channel_layouts=mono";
41 static const char *
player =
"ffplay -f s16le -ar 8000 -ac 1 -";
99 static const int out_sample_rates[] = { 8000, -1 };
104 if (!outputs || !inputs || !filter_graph) {
113 "time_base=%d/%d:sample_rate=%d:sample_fmt=%s:channel_layout=0x%"PRIx64,
117 args,
NULL, filter_graph);
180 &inputs, &outputs,
NULL)) < 0)
188 outlink = buffersink_ctx->
inputs[0];
205 const uint16_t *p = (uint16_t*)frame->
data[0];
206 const uint16_t *p_end = p + n;
209 fputc(*p & 0xff, stdout);
210 fputc(*p>>8 & 0xff, stdout);
216 int main(
int argc,
char **argv)
223 if (!frame || !filt_frame) {
224 perror(
"Could not allocate frame");
228 fprintf(stderr,
"Usage: %s file | %s\n", argv[0],
player);
256 }
else if (ret < 0) {
292 fprintf(stderr,
"Error occurred: %s\n",
av_err2str(ret));
AVFilterContext * buffersink_ctx
This structure describes decoded (raw) audio or video data.
AVFilterGraph * avfilter_graph_alloc(void)
Allocate a filter graph.
Memory buffer source API.
AVFilterGraph * filter_graph
int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx)
Check validity and configure all the links and formats in the graph.
void avfilter_inout_free(AVFilterInOut **inout)
Free the supplied list of AVFilterInOut and set *inout to NULL.
struct AVFilterInOut * next
next input/input in the list, NULL if this is the last
#define av_opt_set_int_list(obj, name, val, term, flags)
Set a binary option to an integer list.
void avfilter_graph_free(AVFilterGraph **graph)
Free a graph, destroy its links, and set *graph to NULL.
static int audio_stream_index
int av_get_channel_layout_nb_channels(uint64_t channel_layout)
Return the number of channels in the channel layout.
memory buffer sink API for audio and video
AVFilterLink ** inputs
array of pointers to input links
enum AVSampleFormat sample_fmt
audio sample format
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
static av_cold int end(AVCodecContext *avctx)
static int init_filters(const char *filters_descr)
static const char * filter_descr
AVStream ** streams
A list of all streams in the file.
int avcodec_parameters_to_context(AVCodecContext *codec, const AVCodecParameters *par)
Fill the codec context based on the values from the supplied codec parameters.
void avfilter_register_all(void)
Initialize the filter system.
int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const AVFilter *filt, const char *name, const char *args, void *opaque, AVFilterGraph *graph_ctx)
Create and add a filter instance into an existing graph.
#define AVERROR_EOF
End of file.
static void * av_x_if_null(const void *p, const void *x)
Return x default pointer in case p is NULL.
A link between two filters.
int av_find_best_stream(AVFormatContext *ic, enum AVMediaType type, int wanted_stream_nb, int related_stream, AVCodec **decoder_ret, int flags)
Find the "best" stream in the file.
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
int main(int argc, char **argv)
int sample_rate
samples per second
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
int avcodec_receive_frame(AVCodecContext *avctx, AVFrame *frame)
Return decoded output data from a decoder.
int av_opt_set_int(void *obj, const char *name, int64_t val, int search_flags)
AVFilterContext * buffersrc_ctx
const char * av_get_sample_fmt_name(enum AVSampleFormat sample_fmt)
Return the name of sample_fmt, or NULL if sample_fmt is not recognized.
uint64_t channel_layout
Audio channel layout.
const AVFilter * avfilter_get_by_name(const char *name)
Get a filter definition matching the given name.
AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)
Allocate an AVCodecContext and set its fields to default values.
#define AV_OPT_SEARCH_CHILDREN
Search in possible children of the given object first.
#define av_err2str(errnum)
Convenience macro, the return value should be used only directly in function arguments but never stan...
static int open_input_file(const char *filename)
static const char * player
static const AVFilterPad outputs[]
AVFilterContext * filter_ctx
filter context associated to this input/output
int format
agreed upon media format
Keep a reference to the frame.
void av_get_channel_layout_string(char *buf, int buf_size, int nb_channels, uint64_t channel_layout)
Return a description of a channel layout.
A linked-list of the inputs/outputs of the filter chain.
int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt)
Supply raw packet data as input to a decoder.
#define AV_LOG_INFO
Standard information.
static const AVFilterPad inputs[]
char * av_strdup(const char *s)
Duplicate a string.
Libavcodec external API header.
AVSampleFormat
Audio sample formats.
void avcodec_free_context(AVCodecContext **avctx)
Free the codec context and everything associated with it and write NULL to the provided pointer...
int sample_rate
samples per second
main external API structure.
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
int pad_idx
index of the filt_ctx pad to use for linking
Rational number (pair of numerator and denominator).
static void print_frame(const AVFrame *frame)
int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options)
Initialize the AVCodecContext to use the given AVCodec.
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
int64_t av_frame_get_channel_layout(const AVFrame *frame)
char * name
unique name for this input/output in the list
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
static AVFormatContext * fmt_ctx
AVFilterInOut * avfilter_inout_alloc(void)
Allocate a single AVFilterInOut entry.
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
static AVCodecContext * dec_ctx
uint64_t channel_layout
channel layout of current buffer (see libavutil/channel_layout.h)
int attribute_align_arg av_buffersrc_add_frame_flags(AVFilterContext *ctx, AVFrame *frame, int flags)
Add a frame to the buffer source.
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
int channels
number of audio channels
int avformat_open_input(AVFormatContext **ps, const char *url, AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
int avfilter_graph_parse_ptr(AVFilterGraph *graph, const char *filters, AVFilterInOut **inputs, AVFilterInOut **outputs, void *log_ctx)
Add a graph described by a string to a graph.
int64_t av_get_default_channel_layout(int nb_channels)
Return default channel layout for a given number of channels.
AVCodecParameters * codecpar
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...
#define AV_CH_LAYOUT_MONO
int attribute_align_arg av_buffersink_get_frame(AVFilterContext *ctx, AVFrame *frame)
Get a frame with filtered data from sink and put it in frame.
This structure stores compressed data.
void av_register_all(void)
Initialize libavformat and register all the muxers, demuxers and protocols.
int nb_samples
number of audio samples (per channel) described by this frame