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authorMax Kellermann <max@duempel.org>2008-10-23 20:02:51 +0200
committerMax Kellermann <max@duempel.org>2008-10-23 20:02:51 +0200
commitaf7cb932fb90204a8d80baf4cba75b82c4a3fd5a (patch)
tree1531e0bf2e8974997ddc10608bf0702c2694dc9f /src
parent5bbcbfb7cee1ba29dcb084066d52e3235019be17 (diff)
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pcm_resample: implemented 24 bit resampling
Similar to pcm_resample_16(), implement pcm_resample_24(). The 24 bit implementation is very similar, but it uses src_int_to_float_array() instead of src_short_to_float_array() before sending data to libsamplerate.
Diffstat (limited to 'src')
-rw-r--r--src/pcm_resample.h8
-rw-r--r--src/pcm_resample_fallback.c33
-rw-r--r--src/pcm_resample_libsamplerate.c53
3 files changed, 94 insertions, 0 deletions
diff --git a/src/pcm_resample.h b/src/pcm_resample.h
index d6001550a..c80dfa8a3 100644
--- a/src/pcm_resample.h
+++ b/src/pcm_resample.h
@@ -60,4 +60,12 @@ pcm_resample_16(uint8_t channels,
int16_t *dest_buffer, size_t dest_size,
struct pcm_resample_state *state);
+size_t
+pcm_resample_24(uint8_t channels,
+ unsigned src_rate,
+ const int32_t *src_buffer, size_t src_size,
+ unsigned dest_rate,
+ int32_t *dest_buffer, size_t dest_size,
+ struct pcm_resample_state *state);
+
#endif
diff --git a/src/pcm_resample_fallback.c b/src/pcm_resample_fallback.c
index 0a913406c..da7dcaabe 100644
--- a/src/pcm_resample_fallback.c
+++ b/src/pcm_resample_fallback.c
@@ -58,3 +58,36 @@ pcm_resample_16(uint8_t channels,
return dest_size;
}
+
+size_t
+pcm_resample_24(uint8_t channels,
+ unsigned src_rate,
+ const int32_t *src_buffer, mpd_unused size_t src_size,
+ unsigned dest_rate,
+ int32_t *dest_buffer, size_t dest_size,
+ mpd_unused struct pcm_resample_state *state)
+{
+ unsigned src_pos, dest_pos = 0;
+ unsigned dest_samples = dest_size / sizeof(*dest_buffer);
+
+ switch (channels) {
+ case 1:
+ while (dest_pos < dest_samples) {
+ src_pos = dest_pos * src_rate / dest_rate;
+
+ dest_buffer[dest_pos++] = src_buffer[src_pos];
+ }
+ break;
+ case 2:
+ while (dest_pos < dest_samples) {
+ src_pos = dest_pos * src_rate / dest_rate;
+ src_pos &= ~1;
+
+ dest_buffer[dest_pos++] = src_buffer[src_pos];
+ dest_buffer[dest_pos++] = src_buffer[src_pos + 1];
+ }
+ break;
+ }
+
+ return dest_size;
+}
diff --git a/src/pcm_resample_libsamplerate.c b/src/pcm_resample_libsamplerate.c
index 503a049b4..43a2a2f26 100644
--- a/src/pcm_resample_libsamplerate.c
+++ b/src/pcm_resample_libsamplerate.c
@@ -153,3 +153,56 @@ pcm_resample_16(uint8_t channels,
return data->output_frames_gen * sizeof(*dest_buffer) * channels;
}
+
+size_t
+pcm_resample_24(uint8_t channels,
+ unsigned src_rate,
+ const int32_t *src_buffer, size_t src_size,
+ unsigned dest_rate,
+ int32_t *dest_buffer, size_t dest_size,
+ struct pcm_resample_state *state)
+{
+ SRC_DATA *data = &state->data;
+ size_t data_in_size;
+ size_t data_out_size;
+ int error;
+
+ assert((src_size % (sizeof(*src_buffer) * channels)) == 0);
+ assert((dest_size % (sizeof(*dest_buffer) * channels)) == 0);
+
+ pcm_resample_set(state, channels, src_rate, dest_rate);
+
+ /* there was an error previously, and nothing has changed */
+ if (state->error)
+ return 0;
+
+ data->input_frames = src_size / sizeof(*src_buffer) / channels;
+ data_in_size = data->input_frames * sizeof(float) * channels;
+ if (data_in_size > state->data_in_size) {
+ state->data_in_size = data_in_size;
+ data->data_in = xrealloc(data->data_in, data_in_size);
+ }
+
+ data->output_frames = dest_size / sizeof(*dest_buffer) / channels;
+ data_out_size = data->output_frames * sizeof(float) * channels;
+ if (data_out_size > state->data_out_size) {
+ state->data_out_size = data_out_size;
+ data->data_out = xrealloc(data->data_out, data_out_size);
+ }
+
+ src_int_to_float_array(src_buffer, data->data_in,
+ data->input_frames * channels);
+
+ error = src_process(state->state, data);
+ if (error) {
+ ERROR("error processing samples with libsamplerate: %s\n",
+ src_strerror(error));
+ state->error = true;
+ return 0;
+ }
+
+ src_float_to_int_array(data->data_out, dest_buffer,
+ data->output_frames_gen * channels);
+
+ return data->output_frames_gen * sizeof(*dest_buffer) * channels;
+}