---
- changed the return value of convert_frame
- added open2
- documented config (open3?)
How to use the new api (will be put somewhere else
AVAudioResampleContext *avr = avresample_alloc();
AVFrame *out = av_frame_alloc();
AVFrame *in;
while (fill_input(in)) {
ret = avresample_convert_frame(avr, out, in);
do_stuff(out);
}
ret = avresample_convert_frame(avr, out, NULL);
do_stuff(out);
libavresample/avresample.h | 77 +++++++++++++++++++++++++
libavresample/utils.c | 138 +++++++++++++++++++++++++++++++++++++++++++++
libavutil/error.h | 2 +
3 files changed, 217 insertions(+)
diff --git a/libavresample/avresample.h b/libavresample/avresample.h
index 3358628..b598d86 100644
--- a/libavresample/avresample.h
+++ b/libavresample/avresample.h
@@ -96,6 +96,7 @@
#include "libavutil/avutil.h"
#include "libavutil/channel_layout.h"
#include "libavutil/dict.h"
+#include "libavutil/frame.h"
#include "libavutil/log.h"
#include "libavresample/version.h"
@@ -172,6 +173,15 @@ AVAudioResampleContext *avresample_alloc_context(void);
int avresample_open(AVAudioResampleContext *avr);
/**
+ * Initialize AVAudioResampleContext.
+ *
+ * @param avr audio resample context
+ * @param opts optional configuration.
+ * @return 0 on success, negative AVERROR code on failure
+ */
+int avresample_open2(AVAudioResampleContext *avr, AVDictionary **opts);
+
+/**
* Check whether an AVAudioResampleContext is open or closed.
*
* @param avr AVAudioResampleContext to check
@@ -410,6 +420,73 @@ int avresample_available(AVAudioResampleContext *avr);
*/
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 given by
+ * avresample_available() + (avresample_get_delay() + number of input samples)
*
+ * output sample rate / input sample rate.
+ *
+ * If the output AVFrame does not have the data pointers allocated a the
nb_samples
+ * will be set as described above and av_frame_get_buffer() will be called.
+ *
+ * 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_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 and an optional AVDictionary containing additional
+ * resampler options.
+ *
+ * The original resampling context is reset even on failure.
+ * The function calls internally avresample_open2().
+ *
+ * @see avresample_open2();
+ *
+ * @param avr audio resample context
+ * @param output output AVFrame
+ * @param input input AVFrame
+ * @return 0 on success, AVERROR on failure.
+ */
+int avresample_config(AVAudioResampleContext *avr, AVFrame *out, AVFrame *in,
+ AVDictionary **opts);
+
/**
* @}
*/
diff --git a/libavresample/utils.c b/libavresample/utils.c
index 35bee42..08e09d8 100644
--- a/libavresample/utils.c
+++ b/libavresample/utils.c
@@ -21,6 +21,7 @@
#include "libavutil/common.h"
#include "libavutil/dict.h"
#include "libavutil/error.h"
+#include "libavutil/frame.h"
#include "libavutil/log.h"
#include "libavutil/mem.h"
#include "libavutil/opt.h"
@@ -506,6 +507,143 @@ int attribute_align_arg
avresample_convert(AVAudioResampleContext *avr,
current_buffer);
}
+int avresample_open2(AVAudioResampleContext *avr, AVDictionary **opts)
+{
+ int ret;
+
+ if ((ret = av_opt_set_dict(avr, opts)) < 0)
+ return ret;
+
+ return avresample_open(avr);
+}
+
+int avresample_config(AVAudioResampleContext *avr, AVFrame *out, AVFrame *in,
+ AVDictionary **opts)
+{
+ if (avresample_is_open(avr)) {
+ avresample_close(avr);
+ }
+
+ if (!out || !in)
+ return AVERROR(EINVAL);
+
+ avr->in_channel_layout = in->channel_layout;
+ avr->out_channel_layout = out->channel_layout;
+ avr->in_sample_rate = in->sample_rate;
+ avr->out_sample_rate = out->sample_rate;
+ avr->in_sample_fmt = in->format;
+ avr->out_sample_fmt = out->format;
+
+ return avresample_open2(avr, opts);
+}
+
+static int config_changed(AVAudioResampleContext *avr,
+ AVFrame *out, AVFrame *in)
+{
+ int ret = 0;
+
+ if (in) {
+ if (avr->in_channel_layout != in->channel_layout ||
+ avr->in_sample_rate != in->sample_rate ||
+ avr->in_sample_fmt != in->format) {
+ ret |= AVERROR_INPUT_CHANGED;
+ }
+ }
+
+ if (out) {
+ if (avr->out_channel_layout != out->channel_layout ||
+ avr->out_sample_rate != out->sample_rate ||
+ avr->out_sample_fmt != out->format) {
+ ret |= AVERROR_OUTPUT_CHANGED;
+ }
+ }
+
+ return ret;
+}
+
+static inline int convert_frame(AVAudioResampleContext *avr,
+ AVFrame *out, AVFrame *in)
+{
+ int ret;
+ uint8_t **out_data = NULL, **in_data = NULL;
+ int out_linesize = 0, in_linesize = 0;
+ int out_nb_samples = 0, in_nb_samples = 0;
+
+ if (out) {
+ out_data = out->extended_data;
+ out_linesize = out->linesize[0];
+ out_nb_samples = out->nb_samples;
+ }
+
+ if (in) {
+ in_data = in->extended_data;
+ in_linesize = in->linesize[0];
+ in_nb_samples = in->nb_samples;
+ }
+
+ ret = avresample_convert(avr, out_data, out_linesize,
+ out_nb_samples,
+ in_data, in_linesize,
+ in_nb_samples);
+
+ if (ret > 0) {
+ out->nb_samples = ret;
+ return 0;
+ }
+
+ return ret;
+}
+
+static inline int optimal_samples(AVAudioResampleContext *avr,
+ AVFrame *out, AVFrame *in)
+{
+ return avresample_available(avr) +
+ (avresample_get_delay(avr) + in->nb_samples) *
+ out->sample_rate / in->sample_rate;
+}
+
+static inline int available_samples(AVFrame *out)
+{
+ int bytes_per_sample = av_get_bytes_per_sample(out->format);
+ int samples = out->linesize[0] / bytes_per_sample;
+
+ if (av_sample_fmt_is_planar(out->format)) {
+ return samples;
+ } else {
+ int channels = av_get_channel_layout_nb_channels(out->channel_layout);
+ return samples / channels;
+ }
+}
+
+int avresample_convert_frame(AVAudioResampleContext *avr,
+ AVFrame *out, AVFrame *in)
+{
+ int ret, setup = 0;
+
+ if (!avresample_is_open(avr)) {
+ if ((ret = avresample_config(avr, out, in, NULL)) < 0)
+ return ret;
+ setup = 1;
+ } else {
+ // return as is or reconfigure for input changes?
+ if ((ret = config_changed(avr, out, in)))
+ return ret;
+ }
+
+ if (out && !out->linesize[0]) {
+ out->nb_samples = optimal_samples(avr, out, in);
+ if ((ret = av_frame_get_buffer(out, 0)) < 0) {
+ if (setup)
+ avresample_close(avr);
+ return ret;
+ }
+ } else {
+ out->nb_samples = available_samples(out);
+ }
+
+ return convert_frame(avr, out, in);
+}
+
int avresample_get_matrix(AVAudioResampleContext *avr, double *matrix,
int stride)
{
diff --git a/libavutil/error.h b/libavutil/error.h
index 268a032..0a95d2e 100644
--- a/libavutil/error.h
+++ b/libavutil/error.h
@@ -60,6 +60,8 @@
#define AVERROR_BUG (-0x5fb8aabe) ///< Bug detected, please
report the issue
#define AVERROR_UNKNOWN (-0x31b4b1ab) ///< Unknown error, typically
from an external library
#define AVERROR_EXPERIMENTAL (-0x2bb2afa8) ///< Requested feature is
flagged experimental. Set strict_std_compliance if you really want to use it.
+#define AVERROR_INPUT_CHANGED (-0x636e6701) ///< Input changed between
calls. Reconfiguration is required.
+#define AVERROR_OUTPUT_CHANGED (-0x636e6702) ///< Output changed between
calls. Reconfiguration is required.
/**
* Put a description of the AVERROR code errnum in errbuf.
--
1.8.5.2 (Apple Git-48)
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