# 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/media/libspeex_resampler/src/resample.c b/media/libspeex_resampler/src/resample.c

--- a/media/libspeex_resampler/src/resample.c

+++ b/media/libspeex_resampler/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/media/libspeex_resampler/src/speex_resampler.h b/media/libspeex_resampler/src/speex_resampler.h

--- a/media/libspeex_resampler/src/speex_resampler.h

+++ b/media/libspeex_resampler/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