2 Copyright (C) 2013-2015 Carl Hetherington <cth@carlh.net>
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 #include "libavutil/channel_layout.h"
22 #include "libavutil/opt.h"
24 #include "resampler.h"
25 #include "audio_buffers.h"
26 #include "exceptions.h"
27 #include "compose.hpp"
34 using boost::shared_ptr;
36 Resampler::Resampler (int in, int out, int channels)
39 , _channels (channels)
41 _swr_context = swr_alloc ();
44 av_opt_set_int (_swr_context, "isf", AV_SAMPLE_FMT_FLTP, 0);
45 av_opt_set_int (_swr_context, "osf", AV_SAMPLE_FMT_FLTP, 0);
48 av_opt_set_int (_swr_context, "ich", _channels, 0);
49 av_opt_set_int (_swr_context, "och", _channels, 0);
52 av_opt_set_int (_swr_context, "isr", _in_rate, 0);
53 av_opt_set_int (_swr_context, "osr", _out_rate, 0);
55 swr_init (_swr_context);
58 Resampler::~Resampler ()
60 swr_free (&_swr_context);
63 shared_ptr<const AudioBuffers>
64 Resampler::run (shared_ptr<const AudioBuffers> in)
66 /* Compute the resampled frames count and add 32 for luck */
67 int const max_resampled_frames = ceil ((double) in->frames() * _out_rate / _in_rate) + 32;
68 shared_ptr<AudioBuffers> resampled (new AudioBuffers (_channels, max_resampled_frames));
70 int const resampled_frames = swr_convert (
71 _swr_context, (uint8_t **) resampled->data(), max_resampled_frames, (uint8_t const **) in->data(), in->frames()
74 if (resampled_frames < 0) {
76 av_strerror (resampled_frames, buf, sizeof(buf));
77 throw EncodeError (String::compose (_("could not run sample-rate converter for %1 samples (%2) (%3)"), in->frames(), resampled_frames, buf));
80 resampled->set_frames (resampled_frames);
84 shared_ptr<const AudioBuffers>
87 shared_ptr<AudioBuffers> out (new AudioBuffers (_channels, 0));
89 int64_t const pass_size = 256;
90 shared_ptr<AudioBuffers> pass (new AudioBuffers (_channels, 256));
93 int const frames = swr_convert (_swr_context, (uint8_t **) pass->data(), pass_size, 0, 0);
96 throw EncodeError (_("could not run sample-rate converter"));
103 out->ensure_size (out_offset + frames);
104 out->copy_from (pass.get(), frames, 0, out_offset);
105 out_offset += frames;
106 out->set_frames (out_offset);