1 /***
2 This file is part of PulseAudio.
3
4 Copyright 2004-2006 Lennart Poettering
5
6 PulseAudio is free software; you can redistribute it and/or modify
7 it under the terms of the GNU Lesser General Public License as published
8 by the Free Software Foundation; either version 2.1 of the License,
9 or (at your option) any later version.
10
11 PulseAudio is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public License
17 along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
18 ***/
19
20 #ifdef HAVE_CONFIG_H
21 #include <config.h>
22 #endif
23
24 #include <samplerate.h>
25
26 #include <pulsecore/resampler.h>
27
libsamplerate_resample(pa_resampler * r,const pa_memchunk * input,unsigned in_n_frames,pa_memchunk * output,unsigned * out_n_frames)28 static unsigned libsamplerate_resample(pa_resampler *r, const pa_memchunk *input, unsigned in_n_frames, pa_memchunk *output, unsigned *out_n_frames) {
29 SRC_DATA data;
30 SRC_STATE *state;
31
32 pa_assert(r);
33 pa_assert(input);
34 pa_assert(output);
35 pa_assert(out_n_frames);
36
37 state = r->impl.data;
38 memset(&data, 0, sizeof(data));
39
40 data.data_in = pa_memblock_acquire_chunk(input);
41 data.input_frames = (long int) in_n_frames;
42
43 data.data_out = pa_memblock_acquire_chunk(output);
44 data.output_frames = (long int) *out_n_frames;
45
46 data.src_ratio = (double) r->o_ss.rate / r->i_ss.rate;
47 data.end_of_input = 0;
48
49 pa_assert_se(src_process(state, &data) == 0);
50
51 pa_memblock_release(input->memblock);
52 pa_memblock_release(output->memblock);
53
54 *out_n_frames = (unsigned) data.output_frames_gen;
55
56 return in_n_frames - data.input_frames_used;
57 }
58
libsamplerate_update_rates(pa_resampler * r)59 static void libsamplerate_update_rates(pa_resampler *r) {
60 SRC_STATE *state;
61 pa_assert(r);
62
63 state = r->impl.data;
64 pa_assert_se(src_set_ratio(state, (double) r->o_ss.rate / r->i_ss.rate) == 0);
65 }
66
libsamplerate_reset(pa_resampler * r)67 static void libsamplerate_reset(pa_resampler *r) {
68 SRC_STATE *state;
69 pa_assert(r);
70
71 state = r->impl.data;
72 pa_assert_se(src_reset(state) == 0);
73 }
74
libsamplerate_free(pa_resampler * r)75 static void libsamplerate_free(pa_resampler *r) {
76 SRC_STATE *state;
77 pa_assert(r);
78
79 state = r->impl.data;
80 if (state)
81 src_delete(state);
82 }
83
pa_resampler_libsamplerate_init(pa_resampler * r)84 int pa_resampler_libsamplerate_init(pa_resampler *r) {
85 int err;
86 SRC_STATE *state;
87
88 pa_assert(r);
89
90 if (!(state = src_new(r->method, r->work_channels, &err)))
91 return -1;
92
93 r->impl.free = libsamplerate_free;
94 r->impl.update_rates = libsamplerate_update_rates;
95 r->impl.resample = libsamplerate_resample;
96 r->impl.reset = libsamplerate_reset;
97 r->impl.data = state;
98
99 return 0;
100 }
101