* while (get_input(&input, &in_linesize, &in_samples)) {
* uint8_t *output
* int out_linesize;
- * int out_samples = avresample_available(avr) +
- * av_rescale_rnd(avresample_get_delay(avr) +
- * in_samples, 44100, 48000, AV_ROUND_UP);
+ * int out_samples = avresample_get_out_samples(avr, in_samples);
+ *
* av_samples_alloc(&output, &out_linesize, 2, out_samples,
* AV_SAMPLE_FMT_S16, 0);
* out_samples = avresample_convert(avr, &output, out_linesize, out_samples,
#include "libavutil/avutil.h"
#include "libavutil/channel_layout.h"
#include "libavutil/dict.h"
+#include "libavutil/frame.h"
#include "libavutil/log.h"
+#include "libavutil/mathematics.h"
#include "libavresample/version.h"
/**
* Initialize AVAudioResampleContext.
+ * @note The context must be configured using the AVOption API.
+ * @note The fields "in_channel_layout", "out_channel_layout",
+ * "in_sample_rate", "out_sample_rate", "in_sample_fmt",
+ * "out_sample_fmt" must be set.
+ *
+ * @see av_opt_set_int()
+ * @see av_opt_set_dict()
+ * @see av_get_default_channel_layout()
*
* @param avr audio resample context
* @return 0 on success, negative AVERROR code on failure
*/
int avresample_open(AVAudioResampleContext *avr);
+/**
+ * Check whether an AVAudioResampleContext is open or closed.
+ *
+ * @param avr AVAudioResampleContext to check
+ * @return 1 if avr is open, 0 if avr is closed.
+ */
+int avresample_is_open(AVAudioResampleContext *avr);
+
/**
* Close AVAudioResampleContext.
*
int avresample_set_matrix(AVAudioResampleContext *avr, const double *matrix,
int stride);
+/**
+ * Set a customized input channel mapping.
+ *
+ * This function can only be called when the allocated context is not open.
+ * Also, the input channel layout must have already been set.
+ *
+ * Calling avresample_close() on the context will clear the channel mapping.
+ *
+ * The map for each input channel specifies the channel index in the source to
+ * use for that particular channel, or -1 to mute the channel. Source channels
+ * can be duplicated by using the same index for multiple input channels.
+ *
+ * Examples:
+ *
+ * Reordering 5.1 AAC order (C,L,R,Ls,Rs,LFE) to Libav order (L,R,C,LFE,Ls,Rs):
+ * { 1, 2, 0, 5, 3, 4 }
+ *
+ * Muting the 3rd channel in 4-channel input:
+ * { 0, 1, -1, 3 }
+ *
+ * Duplicating the left channel of stereo input:
+ * { 0, 0 }
+ *
+ * @param avr audio resample context
+ * @param channel_map customized input channel mapping
+ * @return 0 on success, negative AVERROR code on failure
+ */
+int avresample_set_channel_mapping(AVAudioResampleContext *avr,
+ const int *channel_map);
+
/**
* Set compensation for resampling.
*
int avresample_set_compensation(AVAudioResampleContext *avr, int sample_delta,
int compensation_distance);
+/**
+ * Provide the upper bound on the number of samples the configured
+ * conversion would output.
+ *
+ * @param avr audio resample context
+ * @param in_nb_samples number of input samples
+ *
+ * @return number of samples or AVERROR(EINVAL) if the value
+ * would exceed INT_MAX
+ */
+
+int avresample_get_out_samples(AVAudioResampleContext *avr, int in_nb_samples);
+
/**
* Convert input samples and write them to the output FIFO.
*
- * The upper bound on the number of output samples is given by
- * avresample_available() + (avresample_get_delay() + number of input samples) *
- * output sample rate / input sample rate.
+ * The upper bound on the number of output samples can be obtained through
+ * avresample_get_out_samples().
*
* The output data can be NULL or have fewer allocated samples than required.
* In this case, any remaining samples not written to the output will be added
* samples. To get this data as output, either call avresample_convert() with
* NULL input or call avresample_read().
*
- * @see avresample_available()
+ * @see avresample_get_out_samples()
* @see avresample_read()
* @see avresample_get_delay()
*
* output FIFO
*/
int avresample_convert(AVAudioResampleContext *avr, uint8_t **output,
- int out_plane_size, int out_samples, uint8_t **input,
- int in_plane_size, int in_samples);
+ int out_plane_size, int out_samples,
+ uint8_t * const *input, int in_plane_size,
+ int in_samples);
/**
* Return the number of samples currently in the resampling delay buffer.
*/
int avresample_read(AVAudioResampleContext *avr, uint8_t **output, int nb_samples);
+/**
+ * Convert the samples in the input AVFrame and write them to the output AVFrame.
+ *
+ * Input and output AVFrames must have channel_layout, sample_rate and format set.
+ *
+ * The upper bound on the number of output samples is obtained through
+ * avresample_get_out_samples().
+ *
+ * If the output AVFrame does not have the data pointers allocated the nb_samples
+ * field will be set using avresample_get_out_samples() and av_frame_get_buffer()
+ * is called to allocate the frame.
+ *
+ * The output AVFrame can be NULL or have fewer allocated samples than required.
+ * In this case, any remaining samples not written to the output will be added
+ * to an internal FIFO buffer, to be returned at the next call to this function
+ * or to avresample_convert() or to avresample_read().
+ *
+ * If converting sample rate, there may be data remaining in the internal
+ * resampling delay buffer. avresample_get_delay() tells the number of
+ * remaining samples. To get this data as output, call this function or
+ * avresample_convert() with NULL input.
+ *
+ * At the end of the conversion process, there may be data remaining in the
+ * internal FIFO buffer. avresample_available() tells the number of remaining
+ * samples. To get this data as output, either call this function or
+ * avresample_convert() with NULL input or call avresample_read().
+ *
+ * If the AVAudioResampleContext configuration does not match the output and
+ * input AVFrame settings the conversion does not take place and depending on
+ * which AVFrame is not matching AVERROR_OUTPUT_CHANGED, AVERROR_INPUT_CHANGED
+ * or AVERROR_OUTPUT_CHANGED|AVERROR_INPUT_CHANGED is returned.
+ *
+ * @see avresample_get_out_samples()
+ * @see avresample_available()
+ * @see avresample_convert()
+ * @see avresample_read()
+ * @see avresample_get_delay()
+ *
+ * @param avr audio resample context
+ * @param output output AVFrame
+ * @param input input AVFrame
+ * @return 0 on success, AVERROR on failure or nonmatching
+ * configuration.
+ */
+int avresample_convert_frame(AVAudioResampleContext *avr,
+ AVFrame *output, AVFrame *input);
+
+/**
+ * Configure or reconfigure the AVAudioResampleContext using the information
+ * provided by the AVFrames.
+ *
+ * The original resampling context is reset even on failure.
+ * The function calls avresample_close() internally if the context is open.
+ *
+ * @see avresample_open();
+ * @see avresample_close();
+ *
+ * @param avr audio resample context
+ * @param out output AVFrame
+ * @param in input AVFrame
+ * @return 0 on success, AVERROR on failure.
+ */
+int avresample_config(AVAudioResampleContext *avr, AVFrame *out, AVFrame *in);
+
/**
* @}
*/
projects / ffmpeg / blobdiff