1 files changed, 132 insertions, 0 deletions
diff --git a/src/pulsecore/resampler/ffmpeg.c b/src/pulsecore/resampler/ffmpeg.c
new file mode 100644
index 0000000..388b555
--- /dev/null
+++ b/src/pulsecore/resampler/ffmpeg.c
@@ -0,0 +1,132 @@
+/***
+  This file is part of PulseAudio.
+
+  Copyright 2004-2006 Lennart Poettering
+
+  PulseAudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as published
+  by the Free Software Foundation; either version 2.1 of the License,
+  or (at your option) any later version.
+
+  PulseAudio is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <pulse/xmalloc.h>
+#include "pulsecore/ffmpeg/avcodec.h"
+
+#include <pulsecore/resampler.h>
+
+struct ffmpeg_data { /* data specific to ffmpeg */
+    struct AVResampleContext *state;
+};
+
+static unsigned ffmpeg_resample(pa_resampler *r, const pa_memchunk *input, unsigned in_n_frames, pa_memchunk *output, unsigned *out_n_frames) {
+    unsigned used_frames = 0, c;
+    int previous_consumed_frames = -1;
+    struct ffmpeg_data *ffmpeg_data;
+
+    pa_assert(r);
+    pa_assert(input);
+    pa_assert(output);
+    pa_assert(out_n_frames);
+
+    ffmpeg_data = r->impl.data;
+
+    for (c = 0; c < r->work_channels; c++) {
+        unsigned u;
+        pa_memblock *b, *w;
+        int16_t *p, *t, *k, *q, *s;
+        int consumed_frames;
+
+        /* Allocate a new block */
+        b = pa_memblock_new(r->mempool, in_n_frames * sizeof(int16_t));
+        p = pa_memblock_acquire(b);
+
+        /* Now copy the input data, splitting up channels */
+        t = (int16_t*) pa_memblock_acquire_chunk(input) + c;
+        k = p;
+        for (u = 0; u < in_n_frames; u++) {
+            *k = *t;
+            t += r->work_channels;
+            k ++;
+        }
+        pa_memblock_release(input->memblock);
+
+        /* Allocate buffer for the result */
+        w = pa_memblock_new(r->mempool, *out_n_frames * sizeof(int16_t));
+        q = pa_memblock_acquire(w);
+
+        /* Now, resample */
+        used_frames = (unsigned) av_resample(ffmpeg_data->state,
+                                             q, p,
+                                             &consumed_frames,
+                                             (int) in_n_frames, (int) *out_n_frames,
+                                             c >= (unsigned) (r->work_channels-1));
+
+        pa_memblock_release(b);
+        pa_memblock_unref(b);
+
+        pa_assert(consumed_frames <= (int) in_n_frames);
+        pa_assert(previous_consumed_frames == -1 || consumed_frames == previous_consumed_frames);
+        previous_consumed_frames = consumed_frames;
+
+        /* And place the results in the output buffer */
+        s = (int16_t *) pa_memblock_acquire_chunk(output) + c;
+        for (u = 0; u < used_frames; u++) {
+            *s = *q;
+            q++;
+            s += r->work_channels;
+        }
+        pa_memblock_release(output->memblock);
+        pa_memblock_release(w);
+        pa_memblock_unref(w);
+    }
+
+    *out_n_frames = used_frames;
+
+    return in_n_frames - previous_consumed_frames;
+}
+
+static void ffmpeg_free(pa_resampler *r) {
+    struct ffmpeg_data *ffmpeg_data;
+
+    pa_assert(r);
+
+    ffmpeg_data = r->impl.data;
+    if (ffmpeg_data->state)
+        av_resample_close(ffmpeg_data->state);
+}
+
+int pa_resampler_ffmpeg_init(pa_resampler *r) {
+    struct ffmpeg_data *ffmpeg_data;
+
+    pa_assert(r);
+
+    ffmpeg_data = pa_xnew(struct ffmpeg_data, 1);
+
+    /* We could probably implement different quality levels by
+     * adjusting the filter parameters here. However, ffmpeg
+     * internally only uses these hardcoded values, so let's use them
+     * here for now as well until ffmpeg makes this configurable. */
+
+    if (!(ffmpeg_data->state = av_resample_init((int) r->o_ss.rate, (int) r->i_ss.rate, 16, 10, 0, 0.8))) {
+        pa_xfree(ffmpeg_data);
+        return -1;
+    }
+
+    r->impl.free = ffmpeg_free;
+    r->impl.resample = ffmpeg_resample;
+    r->impl.data = (void *) ffmpeg_data;
+
+    return 0;
+}