Utility function to get the upper bound on the number of samples the
resampler would output.
---
Updated again to use av_rescale_rnd.
Justin, as wm4 pointed out the example is using AV_ROUND_UP and not
AV_ROUND_INF. Which one is the most correct?
doc/APIchanges | 3 +++
libavresample/avresample.h | 28 +++++++++++++++++++++-------
libavresample/utils.c | 20 ++++++++++++++++++++
libavresample/version.h | 2 +-
4 files changed, 45 insertions(+), 8 deletions(-)
diff --git a/doc/APIchanges b/doc/APIchanges
index f392c53..a8845d9 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -13,6 +13,9 @@ libavutil: 2013-12-xx
API changes, most recent first:
+2014-04-xx - xxxxxxx - lavr 1.3.0 - avresample.h
+ Add avresample_max_output_samples
+
2014-04-xx - xxxxxxx - lavc 55.50.3 - avcodec.h
Deprecate CODEC_FLAG_MV0. It is replaced by the flag "mv0" in the
"mpv_flags" private option of the mpegvideo encoders.
diff --git a/libavresample/avresample.h b/libavresample/avresample.h
index 3358628..0d42e88 100644
--- a/libavresample/avresample.h
+++ b/libavresample/avresample.h
@@ -76,9 +76,8 @@
* 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_max_output_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,
@@ -97,6 +96,7 @@
#include "libavutil/channel_layout.h"
#include "libavutil/dict.h"
#include "libavutil/log.h"
+#include "libavutil/mathematics.h"
#include "libavresample/version.h"
@@ -313,11 +313,25 @@ 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_max_output_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_max_output_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
@@ -334,7 +348,7 @@ int avresample_set_compensation(AVAudioResampleContext
*avr, int sample_delta,
* samples. To get this data as output, either call avresample_convert() with
* NULL input or call avresample_read().
*
- * @see avresample_available()
+ * @see avresample_max_output_samples()
* @see avresample_read()
* @see avresample_get_delay()
*
diff --git a/libavresample/utils.c b/libavresample/utils.c
index 35bee42..3ee028f 100644
--- a/libavresample/utils.c
+++ b/libavresample/utils.c
@@ -622,6 +622,26 @@ int avresample_available(AVAudioResampleContext *avr)
return av_audio_fifo_size(avr->out_fifo);
}
+int avresample_max_output_samples(AVAudioResampleContext *avr,
+ int in_nb_samples)
+{
+ int64_t samples = avresample_get_delay(avr) + (int64_t)in_nb_samples;
+
+ if (avr->resample_needed) {
+ samples = av_rescale_rnd(samples,
+ avr->out_sample_rate,
+ avr->in_sample_rate,
+ AV_ROUND_NEAR_INF);
+ }
+
+ samples += avresample_available(avr);
+
+ if (samples > INT_MAX)
+ return AVERROR(EINVAL);
+
+ return samples;
+}
+
int avresample_read(AVAudioResampleContext *avr, uint8_t **output, int
nb_samples)
{
if (!output)
diff --git a/libavresample/version.h b/libavresample/version.h
index ca836e4..e740871 100644
--- a/libavresample/version.h
+++ b/libavresample/version.h
@@ -28,7 +28,7 @@
#include "libavutil/version.h"
#define LIBAVRESAMPLE_VERSION_MAJOR 1
-#define LIBAVRESAMPLE_VERSION_MINOR 2
+#define LIBAVRESAMPLE_VERSION_MINOR 3
#define LIBAVRESAMPLE_VERSION_MICRO 0
#define LIBAVRESAMPLE_VERSION_INT AV_VERSION_INT(LIBAVRESAMPLE_VERSION_MAJOR,
\
--
1.9.0
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