[FFmpeg-cvslog] swresample: Add swr_get_out_samples()
Michael Niedermayer
git at videolan.org
Thu Jun 4 05:38:39 CEST 2015
ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Wed Jun 3 01:22:25 2015 +0200| [cc17b43d8dd324fbae98407124618e746a390a76] | committer: Michael Niedermayer
swresample: Add swr_get_out_samples()
Previous version reviewed-by: Pavel Koshevoy <pkoshevoy at gmail.com>
Previous version reviewed-by: wm4 <nfxjfg at googlemail.com>
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=cc17b43d8dd324fbae98407124618e746a390a76
---
doc/APIchanges | 3 +++
libswresample/resample.c | 20 ++++++++++++++++++++
libswresample/swresample.c | 30 ++++++++++++++++++++++++++++++
libswresample/swresample.h | 25 ++++++++++++++++++++++---
libswresample/swresample_internal.h | 2 ++
libswresample/version.h | 2 +-
6 files changed, 78 insertions(+), 4 deletions(-)
diff --git a/doc/APIchanges b/doc/APIchanges
index e151999..5c36dca 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -15,6 +15,9 @@ libavutil: 2014-08-09
API changes, most recent first:
+2015-06-04 - xxxxxxx - lswr 1.2.100
+ Add swr_get_out_samples()
+
2015-05-27 - xxxxxxx - lavu 54.26.100 - cpu.h
Add AV_CPU_FLAG_AVXSLOW.
diff --git a/libswresample/resample.c b/libswresample/resample.c
index d4c7d06..f2624b5 100644
--- a/libswresample/resample.c
+++ b/libswresample/resample.c
@@ -345,6 +345,25 @@ static int64_t get_delay(struct SwrContext *s, int64_t base){
return av_rescale(num, base, s->in_sample_rate*(int64_t)c->src_incr << c->phase_shift);
}
+static int64_t get_out_samples(struct SwrContext *s, int in_samples) {
+ ResampleContext *c = s->resample;
+ // The + 2 are added to allow implementations to be slightly inaccuarte, they should not be needed currently
+ // They also make it easier to proof that changes and optimizations do not
+ // break the upper bound
+ int64_t num = s->in_buffer_count + 2LL + in_samples;
+ num *= 1 << c->phase_shift;
+ num -= c->index;
+ num = av_rescale_rnd(num, s->out_sample_rate, ((int64_t)s->in_sample_rate) << c->phase_shift, AV_ROUND_UP) + 2;
+
+ if (c->compensation_distance) {
+ if (num > INT_MAX)
+ return AVERROR(EINVAL);
+
+ num = FFMAX(num, (num * c->ideal_dst_incr - 1) / c->dst_incr + 1);
+ }
+ return num;
+}
+
static int resample_flush(struct SwrContext *s) {
AudioData *a= &s->in_buffer;
int i, j, ret;
@@ -414,4 +433,5 @@ struct Resampler const swri_resampler={
set_compensation,
get_delay,
invert_initial_buffer,
+ get_out_samples,
};
diff --git a/libswresample/swresample.c b/libswresample/swresample.c
index 87ad7f8..4aa081b 100644
--- a/libswresample/swresample.c
+++ b/libswresample/swresample.c
@@ -673,11 +673,15 @@ int attribute_align_arg swr_convert(struct SwrContext *s, uint8_t *out_arg[SWR_C
const uint8_t *in_arg [SWR_CH_MAX], int in_count){
AudioData * in= &s->in;
AudioData *out= &s->out;
+ int av_unused max_output;
if (!swr_is_initialized(s)) {
av_log(s, AV_LOG_ERROR, "Context has not been initialized\n");
return AVERROR(EINVAL);
}
+#if ASSERT_LEVEL >1
+ max_output = swr_get_out_samples(s, in_count);
+#endif
while(s->drop_output > 0){
int ret;
@@ -720,6 +724,9 @@ int attribute_align_arg swr_convert(struct SwrContext *s, uint8_t *out_arg[SWR_C
int ret = swr_convert_internal(s, out, out_count, in, in_count);
if(ret>0 && !s->drop_output)
s->outpts += ret * (int64_t)s->in_sample_rate;
+
+ av_assert2(max_output < 0 || ret < 0 || ret <= max_output);
+
return ret;
}else{
AudioData tmp= *in;
@@ -771,6 +778,7 @@ int attribute_align_arg swr_convert(struct SwrContext *s, uint8_t *out_arg[SWR_C
}
if(ret2>0 && !s->drop_output)
s->outpts += ret2 * (int64_t)s->in_sample_rate;
+ av_assert2(max_output < 0 || ret2 < 0 || ret2 <= max_output);
return ret2;
}
}
@@ -822,6 +830,28 @@ int64_t swr_get_delay(struct SwrContext *s, int64_t base){
}
}
+int swr_get_out_samples(struct SwrContext *s, int in_samples)
+{
+ int64_t out_samples;
+
+ if (in_samples < 0)
+ return AVERROR(EINVAL);
+
+ if (s->resampler && s->resample) {
+ if (!s->resampler->get_out_samples)
+ return AVERROR(ENOSYS);
+ out_samples = s->resampler->get_out_samples(s, in_samples);
+ } else {
+ out_samples = s->in_buffer_count + in_samples;
+ av_assert0(s->out_sample_rate == s->in_sample_rate);
+ }
+
+ if (out_samples > INT_MAX)
+ return AVERROR(EINVAL);
+
+ return out_samples;
+}
+
int swr_set_compensation(struct SwrContext *s, int sample_delta, int compensation_distance){
int ret;
diff --git a/libswresample/swresample.h b/libswresample/swresample.h
index 37656a6..e1617f4 100644
--- a/libswresample/swresample.h
+++ b/libswresample/swresample.h
@@ -294,9 +294,10 @@ void swr_close(struct SwrContext *s);
* in and in_count can be set to 0 to flush the last few samples out at the
* end.
*
- * If more input is provided than output space then the input will be buffered.
- * You can avoid this buffering by providing more output space than input.
- * Conversion will run directly without copying whenever possible.
+ * If more input is provided than output space, then the input will be buffered.
+ * You can avoid this buffering by using swr_get_out_samples() to retrieve an
+ * upper bound on the required number of output samples for the given number of
+ * input samples. Conversion will run directly without copying whenever possible.
*
* @param s allocated Swr context, with parameters set
* @param out output buffers, only the first one need be set in case of packed audio
@@ -436,6 +437,24 @@ int swr_inject_silence(struct SwrContext *s, int count);
int64_t swr_get_delay(struct SwrContext *s, int64_t base);
/**
+ * Find an upper bound on the number of samples that the next swr_convert
+ * call will output, if called with in_samples of input samples. This
+ * depends on the internal state, and anything changing the internal state
+ * (like further swr_convert() calls) will may change the number of samples
+ * swr_get_out_samples() returns for the same number of input samples.
+ *
+ * @param in_samples number of input samples.
+ * @note any call to swr_inject_silence(), swr_convert(), swr_next_pts()
+ * or swr_set_compensation() invalidates this limit
+ * @note it is recommended to pass the correct available buffer size
+ * to all functions like swr_convert() even if swr_get_out_samples()
+ * indicates that less would be used.
+ * @returns an upper bound on the number of samples that the next swr_convert
+ * will output or a negative value to indicate an error
+ */
+int swr_get_out_samples(struct SwrContext *s, int in_samples);
+
+/**
* @}
*
* @name Configuration accessors
diff --git a/libswresample/swresample_internal.h b/libswresample/swresample_internal.h
index 7745939..7595588 100644
--- a/libswresample/swresample_internal.h
+++ b/libswresample/swresample_internal.h
@@ -76,6 +76,7 @@ typedef int (* resample_flush_func)(struct SwrContext *c);
typedef int (* set_compensation_func)(struct ResampleContext *c, int sample_delta, int compensation_distance);
typedef int64_t (* get_delay_func)(struct SwrContext *s, int64_t base);
typedef int (* invert_initial_buffer_func)(struct ResampleContext *c, AudioData *dst, const AudioData *src, int src_size, int *dst_idx, int *dst_count);
+typedef int64_t (* get_out_samples_func)(struct SwrContext *s, int in_samples);
struct Resampler {
resample_init_func init;
@@ -85,6 +86,7 @@ struct Resampler {
set_compensation_func set_compensation;
get_delay_func get_delay;
invert_initial_buffer_func invert_initial_buffer;
+ get_out_samples_func get_out_samples;
};
extern struct Resampler const swri_resampler;
diff --git a/libswresample/version.h b/libswresample/version.h
index 61c76fa..94ac9c5 100644
--- a/libswresample/version.h
+++ b/libswresample/version.h
@@ -29,7 +29,7 @@
#include "libavutil/avutil.h"
#define LIBSWRESAMPLE_VERSION_MAJOR 1
-#define LIBSWRESAMPLE_VERSION_MINOR 1
+#define LIBSWRESAMPLE_VERSION_MINOR 2
#define LIBSWRESAMPLE_VERSION_MICRO 100
#define LIBSWRESAMPLE_VERSION_INT AV_VERSION_INT(LIBSWRESAMPLE_VERSION_MAJOR, \
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