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# HG changeset patch
# User Karl Tomlinson <karlt+@karlt.net>
b=913854 add speex_resampler_set_skip_frac_num r=jmspeex
This allows a client to align output samples consistently for independent
resampling of contiguous input buffers.
diff --git a/src/resample.c b/src/resample.c
--- a/src/resample.c
+++ b/src/resample.c
@@ -1128,16 +1128,28 @@ EXPORT int speex_resampler_get_output_la
EXPORT int speex_resampler_skip_zeros(SpeexResamplerState *st)
{
spx_uint32_t i;
for (i=0;i<st->nb_channels;i++)
st->last_sample[i] = st->filt_len/2;
return RESAMPLER_ERR_SUCCESS;
}
+EXPORT int speex_resampler_set_skip_frac_num(SpeexResamplerState *st, spx_uint32_t skip_frac_num)
+{
+ spx_uint32_t i;
+ spx_uint32_t last_sample = skip_frac_num / st->den_rate;
+ spx_uint32_t samp_frac_num = skip_frac_num % st->den_rate;
+ for (i=0;i<st->nb_channels;i++) {
+ st->last_sample[i] = last_sample;
+ st->samp_frac_num[i] = samp_frac_num;
+ }
+ return RESAMPLER_ERR_SUCCESS;
+}
+
EXPORT int speex_resampler_reset_mem(SpeexResamplerState *st)
{
spx_uint32_t i;
for (i=0;i<st->nb_channels;i++)
{
st->last_sample[i] = 0;
st->magic_samples[i] = 0;
st->samp_frac_num[i] = 0;
diff --git a/src/speex_resampler.h b/src/speex_resampler.h
--- a/src/speex_resampler.h
+++ b/src/speex_resampler.h
@@ -69,16 +69,17 @@
#define speex_resampler_get_quality CAT_PREFIX(RANDOM_PREFIX,_resampler_get_quality)
#define speex_resampler_set_input_stride CAT_PREFIX(RANDOM_PREFIX,_resampler_set_input_stride)
#define speex_resampler_get_input_stride CAT_PREFIX(RANDOM_PREFIX,_resampler_get_input_stride)
#define speex_resampler_set_output_stride CAT_PREFIX(RANDOM_PREFIX,_resampler_set_output_stride)
#define speex_resampler_get_output_stride CAT_PREFIX(RANDOM_PREFIX,_resampler_get_output_stride)
#define speex_resampler_get_input_latency CAT_PREFIX(RANDOM_PREFIX,_resampler_get_input_latency)
#define speex_resampler_get_output_latency CAT_PREFIX(RANDOM_PREFIX,_resampler_get_output_latency)
#define speex_resampler_skip_zeros CAT_PREFIX(RANDOM_PREFIX,_resampler_skip_zeros)
+#define speex_resampler_set_skip_frac_num CAT_PREFIX(RANDOM_PREFIX,_resampler_set_skip_frac_num)
#define speex_resampler_reset_mem CAT_PREFIX(RANDOM_PREFIX,_resampler_reset_mem)
#define speex_resampler_strerror CAT_PREFIX(RANDOM_PREFIX,_resampler_strerror)
#define spx_int16_t short
#define spx_int32_t int
#define spx_uint16_t unsigned short
#define spx_uint32_t unsigned int
@@ -317,16 +318,32 @@ int speex_resampler_get_output_latency(S
* resampler. It is recommended to use that when resampling an audio file, as
* it will generate a file with the same length. For real-time processing,
* it is probably easier not to use this call (so that the output duration
* is the same for the first frame).
* @param st Resampler state
*/
int speex_resampler_skip_zeros(SpeexResamplerState *st);
+/** Set the numerator in a fraction determining the advance through input
+ * samples before writing any output samples. The denominator of the fraction
+ * is the value returned from speex_resampler_get_ratio() in ratio_den. This
+ * is only useful before starting to use a newly created or reset resampler.
+ * If the first input sample is interpreted as the signal at time
+ * input_latency*in_rate, then the first output sample represents the signal
+ * at the time frac_num/ratio_num*out_rate.
+ * This is intended for careful alignment of output sample points wrt input
+ * sample points. Large values are not an efficient offset into the in buffer.
+ * @param st Resampler state
+ * @param skip_frac_num Numerator of the offset fraction,
+ * between 0 and ratio_den-1.
+ */
+int speex_resampler_set_skip_frac_num(SpeexResamplerState *st,
+ spx_uint32_t skip_frac_num);
+
/** Reset a resampler so a new (unrelated) stream can be processed.
* @param st Resampler state
*/
int speex_resampler_reset_mem(SpeexResamplerState *st);
/** Returns the English meaning for an error code
* @param err Error code
* @return English string