1 files changed, 752 insertions, 347 deletions

diff --git a/src/pulsecore/resampler.c b/src/pulsecore/resampler.c
index 3827ff94..5bbc6bf4 100644
--- a/src/pulsecore/resampler.c
+++ b/src/pulsecore/resampler.c
@@ -25,53 +25,133 @@
 #include <config.h>
 #endif
 
-#include <assert.h>
 #include <string.h>
 
+#if HAVE_LIBSAMPLERATE
 #include <samplerate.h>
+#endif
+
 #include <liboil/liboilfuncs.h>
 #include <liboil/liboil.h>
 
 #include <pulse/xmalloc.h>
-
 #include <pulsecore/sconv.h>
 #include <pulsecore/log.h>
+#include <pulsecore/macro.h>
+
+#include "speexwrap.h"
+
+#include "ffmpeg/avcodec.h"
 
 #include "resampler.h"
 
+/* Number of samples of extra space we allow the resamplers to return */
+#define EXTRA_SAMPLES 128
+
 struct pa_resampler {
     pa_resample_method_t resample_method;
     pa_sample_spec i_ss, o_ss;
     pa_channel_map i_cm, o_cm;
-    size_t i_fz, o_fz;
+    size_t i_fz, o_fz, w_sz;
     pa_mempool *mempool;
 
-    void (*impl_free)(pa_resampler *r);
-    void (*impl_update_input_rate)(pa_resampler *r, uint32_t rate);
-    void (*impl_run)(pa_resampler *r, const pa_memchunk *in, pa_memchunk *out);
-    void *impl_data;
-};
-
-struct impl_libsamplerate {
-    pa_memblock *buf1_block, *buf2_block, *buf3_block, *buf4_block;
-    float* buf1, *buf2, *buf3, *buf4;
+    pa_memchunk buf1, buf2, buf3, buf4;
     unsigned buf1_samples, buf2_samples, buf3_samples, buf4_samples;
 
-    pa_convert_to_float32ne_func_t to_float32ne_func;
-    pa_convert_from_float32ne_func_t from_float32ne_func;
-    SRC_STATE *src_state;
+    pa_sample_format_t work_format;
+
+    pa_convert_func_t to_work_format_func;
+    pa_convert_func_t from_work_format_func;
 
     int map_table[PA_CHANNELS_MAX][PA_CHANNELS_MAX];
     int map_required;
-};
 
-struct impl_trivial {
-    unsigned o_counter;
-    unsigned i_counter;
+    void (*impl_free)(pa_resampler *r);
+    void (*impl_update_rates)(pa_resampler *r);
+    void (*impl_resample)(pa_resampler *r, const pa_memchunk *in, unsigned in_samples, pa_memchunk *out, unsigned *out_samples);
+
+    struct { /* data specific to the trivial resampler */
+        unsigned o_counter;
+        unsigned i_counter;
+    } trivial;
+
+#ifdef HAVE_LIBSAMPLERATE
+    struct { /* data specific to libsamplerate */
+        SRC_STATE *state;
+    } src;
+#endif
+
+    struct { /* data specific to speex */
+        SpeexResamplerState* state;
+    } speex;
+
+    struct { /* data specific to ffmpeg */
+        struct AVResampleContext *state;
+        pa_memchunk buf[PA_CHANNELS_MAX];
+    } ffmpeg;
 };
 
-static int libsamplerate_init(pa_resampler*r);
+static int copy_init(pa_resampler *r);
 static int trivial_init(pa_resampler*r);
+static int speex_init(pa_resampler*r);
+static int ffmpeg_init(pa_resampler*r);
+#ifdef HAVE_LIBSAMPLERATE
+static int libsamplerate_init(pa_resampler*r);
+#endif
+
+static void calc_map_table(pa_resampler *r);
+
+static int (* const init_table[])(pa_resampler*r) = {
+#ifdef HAVE_LIBSAMPLERATE
+    [PA_RESAMPLER_SRC_SINC_BEST_QUALITY]   = libsamplerate_init,
+    [PA_RESAMPLER_SRC_SINC_MEDIUM_QUALITY] = libsamplerate_init,
+    [PA_RESAMPLER_SRC_SINC_FASTEST]        = libsamplerate_init,
+    [PA_RESAMPLER_SRC_ZERO_ORDER_HOLD]     = libsamplerate_init,
+    [PA_RESAMPLER_SRC_LINEAR]              = libsamplerate_init,
+#else
+    [PA_RESAMPLER_SRC_SINC_BEST_QUALITY]   = NULL,
+    [PA_RESAMPLER_SRC_SINC_MEDIUM_QUALITY] = NULL,
+    [PA_RESAMPLER_SRC_SINC_FASTEST]        = NULL,
+    [PA_RESAMPLER_SRC_ZERO_ORDER_HOLD]     = NULL,
+    [PA_RESAMPLER_SRC_LINEAR]              = NULL,
+#endif
+    [PA_RESAMPLER_TRIVIAL]                 = trivial_init,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+0]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+1]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+2]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+3]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+4]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+5]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+6]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+7]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+8]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+9]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+10]     = speex_init,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+0]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+1]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+2]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+3]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+4]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+5]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+6]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+7]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+8]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+9]      = speex_init,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+10]     = speex_init,
+    [PA_RESAMPLER_FFMPEG]                  = ffmpeg_init,
+    [PA_RESAMPLER_AUTO]                    = NULL,
+    [PA_RESAMPLER_COPY]                    = copy_init
+};
+
+static inline size_t sample_size(pa_sample_format_t f) {
+    pa_sample_spec ss = {
+        .format = f,
+        .rate = 0,
+        .channels = 1
+    };
+
+    return pa_sample_size(&ss);
+}
 
 pa_resampler* pa_resampler_new(
         pa_mempool *pool,
@@ -79,25 +159,51 @@ pa_resampler* pa_resampler_new(
         const pa_channel_map *am,
         const pa_sample_spec *b,
         const pa_channel_map *bm,
-        pa_resample_method_t resample_method) {
+        pa_resample_method_t resample_method,
+        int variable_rate) {
 
     pa_resampler *r = NULL;
 
-    assert(pool);
-    assert(a);
-    assert(b);
-    assert(pa_sample_spec_valid(a));
-    assert(pa_sample_spec_valid(b));
-    assert(resample_method != PA_RESAMPLER_INVALID);
+    pa_assert(pool);
+    pa_assert(a);
+    pa_assert(b);
+    pa_assert(pa_sample_spec_valid(a));
+    pa_assert(pa_sample_spec_valid(b));
+    pa_assert(resample_method >= 0);
+    pa_assert(resample_method < PA_RESAMPLER_MAX);
+
+    /* Fix method */
+
+    if (!variable_rate && a->rate == b->rate) {
+        pa_log_info("Forcing resampler 'copy', because of fixed, identical sample rates.");
+        resample_method = PA_RESAMPLER_COPY;
+    }
+
+    if (!pa_resample_method_supported(resample_method)) {
+        pa_log_warn("Support for resampler '%s' not compiled in, reverting to 'auto'.", pa_resample_method_to_string(resample_method));
+        resample_method = PA_RESAMPLER_AUTO;
+    }
+
+    if (resample_method == PA_RESAMPLER_FFMPEG && variable_rate) {
+        pa_log_info("Resampler 'ffmpeg' cannot do variable rate, reverting to resampler 'auto'.");
+        resample_method = PA_RESAMPLER_AUTO;
+    }
+
+    if (resample_method == PA_RESAMPLER_COPY && (variable_rate || a->rate != b->rate)) {
+        pa_log_info("Resampler 'copy' cannot change sampling rate, reverting to resampler 'auto'.");
+        resample_method = PA_RESAMPLER_AUTO;
+    }
+
+    if (resample_method == PA_RESAMPLER_AUTO)
+        resample_method = PA_RESAMPLER_SPEEX_FLOAT_BASE + 0;
 
     r = pa_xnew(pa_resampler, 1);
-    r->impl_data = NULL;
     r->mempool = pool;
     r->resample_method = resample_method;
 
     r->impl_free = NULL;
-    r->impl_update_input_rate = NULL;
-    r->impl_run = NULL;
+    r->impl_update_rates = NULL;
+    r->impl_resample = NULL;
 
     /* Fill sample specs */
     r->i_ss = *a;
@@ -116,25 +222,66 @@ pa_resampler* pa_resampler_new(
     r->i_fz = pa_frame_size(a);
     r->o_fz = pa_frame_size(b);
 
-    /* Choose implementation */
-    if (a->channels != b->channels ||
-        a->format != b->format ||
-        !pa_channel_map_equal(&r->i_cm, &r->o_cm) ||
-        resample_method != PA_RESAMPLER_TRIVIAL) {
+    pa_memchunk_reset(&r->buf1);
+    pa_memchunk_reset(&r->buf2);
+    pa_memchunk_reset(&r->buf3);
+    pa_memchunk_reset(&r->buf4);
+
+    r->buf1_samples = r->buf2_samples = r->buf3_samples = r->buf4_samples = 0;
+
+    calc_map_table(r);
+
+    pa_log_info("Using resampler '%s'", pa_resample_method_to_string(resample_method));
+
+    if ((resample_method >= PA_RESAMPLER_SPEEX_FIXED_BASE && resample_method <= PA_RESAMPLER_SPEEX_FIXED_MAX) ||
+        (resample_method == PA_RESAMPLER_FFMPEG))
+        r->work_format = PA_SAMPLE_S16NE;
+    else if (resample_method == PA_RESAMPLER_TRIVIAL || resample_method == PA_RESAMPLER_COPY) {
 
-        /* Use the libsamplerate based resampler for the complicated cases */
-        if (resample_method == PA_RESAMPLER_TRIVIAL)
-            r->resample_method = PA_RESAMPLER_SRC_ZERO_ORDER_HOLD;
+        if (r->map_required || a->format != b->format) {
 
-        if (libsamplerate_init(r) < 0)
+            if (a->format == PA_SAMPLE_FLOAT32NE || a->format == PA_SAMPLE_FLOAT32RE ||
+                b->format == PA_SAMPLE_FLOAT32NE || b->format == PA_SAMPLE_FLOAT32RE)
+                r->work_format = PA_SAMPLE_FLOAT32NE;
+            else
+                r->work_format = PA_SAMPLE_S16NE;
+
+        } else
+            r->work_format = a->format;
+
+    } else
+        r->work_format = PA_SAMPLE_FLOAT32NE;
+
+    pa_log_info("Using %s as working format.", pa_sample_format_to_string(r->work_format));
+
+    r->w_sz = sample_size(r->work_format);
+
+    if (r->i_ss.format == r->work_format)
+        r->to_work_format_func = NULL;
+    else if (r->work_format == PA_SAMPLE_FLOAT32NE) {
+        if (!(r->to_work_format_func = pa_get_convert_to_float32ne_function(r->i_ss.format)))
+            goto fail;
+    } else {
+        pa_assert(r->work_format == PA_SAMPLE_S16NE);
+        if (!(r->to_work_format_func = pa_get_convert_to_s16ne_function(r->i_ss.format)))
             goto fail;
+    }
 
+    if (r->o_ss.format == r->work_format)
+        r->from_work_format_func = NULL;
+    else if (r->work_format == PA_SAMPLE_FLOAT32NE) {
+        if (!(r->from_work_format_func = pa_get_convert_from_float32ne_function(r->o_ss.format)))
+            goto fail;
     } else {
-        /* Use our own simple non-fp resampler for the trivial cases and when the user selects it */
-        if (trivial_init(r) < 0)
+        pa_assert(r->work_format == PA_SAMPLE_S16NE);
+        if (!(r->from_work_format_func = pa_get_convert_from_s16ne_function(r->o_ss.format)))
             goto fail;
     }
 
+    /* initialize implementation */
+    if (init_table[resample_method](r) < 0)
+        goto fail;
+
     return r;
 
 fail:
@@ -145,41 +292,85 @@ fail:
 }
 
 void pa_resampler_free(pa_resampler *r) {
-    assert(r);
+    pa_assert(r);
 
     if (r->impl_free)
         r->impl_free(r);
 
+    if (r->buf1.memblock)
+        pa_memblock_unref(r->buf1.memblock);
+    if (r->buf2.memblock)
+        pa_memblock_unref(r->buf2.memblock);
+    if (r->buf3.memblock)
+        pa_memblock_unref(r->buf3.memblock);
+    if (r->buf4.memblock)
+        pa_memblock_unref(r->buf4.memblock);
+
     pa_xfree(r);
 }
 
 void pa_resampler_set_input_rate(pa_resampler *r, uint32_t rate) {
-    assert(r);
-    assert(rate > 0);
+    pa_assert(r);
+    pa_assert(rate > 0);
 
     if (r->i_ss.rate == rate)
         return;
 
     r->i_ss.rate = rate;
 
-    if (r->impl_update_input_rate)
-        r->impl_update_input_rate(r, rate);
+    r->impl_update_rates(r);
 }
 
-void pa_resampler_run(pa_resampler *r, const pa_memchunk *in, pa_memchunk *out) {
-    assert(r && in && out && r->impl_run);
+void pa_resampler_set_output_rate(pa_resampler *r, uint32_t rate) {
+    pa_assert(r);
+    pa_assert(rate > 0);
 
-    r->impl_run(r, in, out);
+    if (r->o_ss.rate == rate)
+        return;
+
+    r->o_ss.rate = rate;
+
+    r->impl_update_rates(r);
 }
 
 size_t pa_resampler_request(pa_resampler *r, size_t out_length) {
-    assert(r);
+    pa_assert(r);
 
     return (((out_length / r->o_fz)*r->i_ss.rate)/r->o_ss.rate) * r->i_fz;
 }
 
+size_t pa_resampler_max_block_size(pa_resampler *r) {
+    size_t block_size_max;
+    pa_sample_spec ss;
+    size_t fs;
+
+    pa_assert(r);
+
+    block_size_max = pa_mempool_block_size_max(r->mempool);
+
+    /* We deduce the "largest" sample spec we're using during the
+     * conversion */
+    ss = r->i_ss;
+    if (r->o_ss.channels > ss.channels)
+        ss.channels = r->o_ss.channels;
+
+    /* We silently assume that the format enum is ordered by size */
+    if (r->o_ss.format > ss.format)
+        ss.format = r->o_ss.format;
+    if (r->work_format > ss.format)
+        ss.format = r->work_format;
+
+    if (r->o_ss.rate > ss.rate)
+        ss.rate = r->o_ss.rate;
+
+    fs = pa_frame_size(&ss);
+
+    return (((block_size_max/fs + EXTRA_SAMPLES)*r->i_ss.rate)/ss.rate)*r->i_fz;
+}
+
 pa_resample_method_t pa_resampler_get_method(pa_resampler *r) {
-    assert(r);
+    pa_assert(r);
+
     return r->resample_method;
 }
 
@@ -189,7 +380,32 @@ static const char * const resample_methods[] = {
     "src-sinc-fastest",
     "src-zero-order-hold",
     "src-linear",
-    "trivial"
+    "trivial",
+    "speex-float-0",
+    "speex-float-1",
+    "speex-float-2",
+    "speex-float-3",
+    "speex-float-4",
+    "speex-float-5",
+    "speex-float-6",
+    "speex-float-7",
+    "speex-float-8",
+    "speex-float-9",
+    "speex-float-10",
+    "speex-fixed-0",
+    "speex-fixed-1",
+    "speex-fixed-2",
+    "speex-fixed-3",
+    "speex-fixed-4",
+    "speex-fixed-5",
+    "speex-fixed-6",
+    "speex-fixed-7",
+    "speex-fixed-8",
+    "speex-fixed-9",
+    "speex-fixed-10",
+    "ffmpeg",
+    "auto",
+    "copy"
 };
 
 const char *pa_resample_method_to_string(pa_resample_method_t m) {
@@ -200,52 +416,43 @@ const char *pa_resample_method_to_string(pa_resample_method_t m) {
     return resample_methods[m];
 }
 
-pa_resample_method_t pa_parse_resample_method(const char *string) {
-    pa_resample_method_t m;
+int pa_resample_method_supported(pa_resample_method_t m) {
 
-    assert(string);
+    if (m < 0 || m >= PA_RESAMPLER_MAX)
+        return 0;
 
-    for (m = 0; m < PA_RESAMPLER_MAX; m++)
-        if (!strcmp(string, resample_methods[m]))
-            return m;
+#ifndef HAVE_LIBSAMPLERATE
+    if (m <= PA_RESAMPLER_SRC_LINEAR)
+        return 0;
+#endif
 
-    return PA_RESAMPLER_INVALID;
+    return 1;
 }
 
+pa_resample_method_t pa_parse_resample_method(const char *string) {
+    pa_resample_method_t m;
 
-/*** libsamplerate based implementation ***/
-
-static void libsamplerate_free(pa_resampler *r) {
-    struct impl_libsamplerate *u;
+    pa_assert(string);
 
-    assert(r);
-    assert(r->impl_data);
+    for (m = 0; m < PA_RESAMPLER_MAX; m++)
+        if (!strcmp(string, resample_methods[m]))
+            return m;
 
-    u = r->impl_data;
+    if (!strcmp(string, "speex-fixed"))
+        return PA_RESAMPLER_SPEEX_FIXED_BASE + 0;
 
-    if (u->src_state)
-        src_delete(u->src_state);
+    if (!strcmp(string, "speex-float"))
+        return PA_RESAMPLER_SPEEX_FLOAT_BASE + 0;
 
-    if (u->buf1_block)
-        pa_memblock_unref(u->buf1_block);
-    if (u->buf2_block)
-        pa_memblock_unref(u->buf2_block);
-    if (u->buf3_block)
-        pa_memblock_unref(u->buf3_block);
-    if (u->buf4_block)
-        pa_memblock_unref(u->buf4_block);
-    pa_xfree(u);
+    return PA_RESAMPLER_INVALID;
 }
 
 static void calc_map_table(pa_resampler *r) {
-    struct impl_libsamplerate *u;
     unsigned oc;
-    assert(r);
-    assert(r->impl_data);
 
-    u = r->impl_data;
+    pa_assert(r);
 
-    if (!(u->map_required = (!pa_channel_map_equal(&r->i_cm, &r->o_cm) || r->i_ss.channels != r->o_ss.channels)))
+    if (!(r->map_required = (r->i_ss.channels != r->o_ss.channels || !pa_channel_map_equal(&r->i_cm, &r->o_cm))))
         return;
 
     for (oc = 0; oc < r->o_ss.channels; oc++) {
@@ -263,392 +470,590 @@ static void calc_map_table(pa_resampler *r) {
                 (a == PA_CHANNEL_POSITION_LEFT && b == PA_CHANNEL_POSITION_MONO) ||
                 (a == PA_CHANNEL_POSITION_RIGHT && b == PA_CHANNEL_POSITION_MONO))
 
-                u->map_table[oc][i++] = ic;
+                r->map_table[oc][i++] = ic;
         }
 
         /* Add an end marker */
         if (i < PA_CHANNELS_MAX)
-            u->map_table[oc][i] = -1;
+            r->map_table[oc][i] = -1;
     }
 }
 
-static float * convert_to_float(pa_resampler *r, void *input, unsigned n_frames) {
-    struct impl_libsamplerate *u;
+static pa_memchunk* convert_to_work_format(pa_resampler *r, pa_memchunk *input) {
     unsigned n_samples;
+    void *src, *dst;
 
-    assert(r);
-    assert(input);
-    assert(r->impl_data);
-    u = r->impl_data;
+    pa_assert(r);
+    pa_assert(input);
+    pa_assert(input->memblock);
 
-    /* Convert the incoming sample into floats and place them in buf1 */
+    /* Convert the incoming sample into the work sample format and place them in buf1 */
 
-    if (!u->to_float32ne_func)
+    if (!r->to_work_format_func || !input->length)
         return input;
 
-    n_samples = n_frames * r->i_ss.channels;
+    n_samples = (input->length / r->i_fz) * r->i_ss.channels;
 
-    if (u->buf1_samples < n_samples) {
-        if (u->buf1_block)
-            pa_memblock_unref(u->buf1_block);
+    r->buf1.index = 0;
+    r->buf1.length = r->w_sz * n_samples;
 
-        u->buf1_samples = n_samples;
-        u->buf1_block = pa_memblock_new(r->mempool, sizeof(float) * n_samples);
-        u->buf1 = u->buf1_block->data;
+    if (!r->buf1.memblock || r->buf1_samples < n_samples) {
+        if (r->buf1.memblock)
+            pa_memblock_unref(r->buf1.memblock);
+
+        r->buf1_samples = n_samples;
+        r->buf1.memblock = pa_memblock_new(r->mempool, r->buf1.length);
     }
 
-    u->to_float32ne_func(n_samples, input, u->buf1);
+    src = (uint8_t*) pa_memblock_acquire(input->memblock) + input->index;
+    dst = (uint8_t*) pa_memblock_acquire(r->buf1.memblock);
+
+    r->to_work_format_func(n_samples, src, dst);
+
+    pa_memblock_release(input->memblock);
+    pa_memblock_release(r->buf1.memblock);
 
-    return u->buf1;
+    return &r->buf1;
 }
 
-static float *remap_channels(pa_resampler *r, float *input, unsigned n_frames) {
-    struct impl_libsamplerate *u;
-    unsigned n_samples;
+static pa_memchunk *remap_channels(pa_resampler *r, pa_memchunk *input) {
+    unsigned in_n_samples, out_n_samples, n_frames;
     int i_skip, o_skip;
     unsigned oc;
+    void *src, *dst;
 
-    assert(r);
-    assert(input);
-    assert(r->impl_data);
-    u = r->impl_data;
+    pa_assert(r);
+    pa_assert(input);
+    pa_assert(input->memblock);
 
     /* Remap channels and place the result int buf2 */
 
-    if (!u->map_required)
+    if (!r->map_required || !input->length)
         return input;
 
-    n_samples = n_frames * r->o_ss.channels;
+    in_n_samples = input->length / r->w_sz;
+    n_frames = in_n_samples / r->i_ss.channels;
+    out_n_samples = n_frames * r->o_ss.channels;
+
+    r->buf2.index = 0;
+    r->buf2.length = r->w_sz * out_n_samples;
 
-    if (u->buf2_samples < n_samples) {
-        if (u->buf2_block)
-            pa_memblock_unref(u->buf2_block);
+    if (!r->buf2.memblock || r->buf2_samples < out_n_samples) {
+        if (r->buf2.memblock)
+            pa_memblock_unref(r->buf2.memblock);
 
-        u->buf2_samples = n_samples;
-        u->buf2_block = pa_memblock_new(r->mempool, sizeof(float) * n_samples);
-        u->buf2 = u->buf2_block->data;
+        r->buf2_samples = out_n_samples;
+        r->buf2.memblock = pa_memblock_new(r->mempool, r->buf2.length);
     }
 
-    memset(u->buf2, 0, n_samples * sizeof(float));
+    src = ((uint8_t*) pa_memblock_acquire(input->memblock) + input->index);
+    dst = pa_memblock_acquire(r->buf2.memblock);
 
-    o_skip = sizeof(float) * r->o_ss.channels;
-    i_skip = sizeof(float) * r->i_ss.channels;
+    memset(dst, 0, r->buf2.length);
 
-    for (oc = 0; oc < r->o_ss.channels; oc++) {
-        unsigned i;
-        static const float one = 1.0;
-
-        for (i = 0; i < PA_CHANNELS_MAX && u->map_table[oc][i] >= 0; i++)
-            oil_vectoradd_f32(
-                u->buf2 + oc, o_skip,
-                u->buf2 + oc, o_skip,
-                input + u->map_table[oc][i], i_skip,
-                n_frames,
-                &one, &one);
+    o_skip = r->w_sz * r->o_ss.channels;
+    i_skip = r->w_sz * r->i_ss.channels;
+
+    switch (r->work_format) {
+        case PA_SAMPLE_FLOAT32NE:
+
+            for (oc = 0; oc < r->o_ss.channels; oc++) {
+                unsigned i;
+                static const float one = 1.0;
+
+                for (i = 0; i < PA_CHANNELS_MAX && r->map_table[oc][i] >= 0; i++)
+                    oil_vectoradd_f32(
+                            (float*) dst + oc, o_skip,
+                            (float*) dst + oc, o_skip,
+                            (float*) src + r->map_table[oc][i], i_skip,
+                            n_frames,
+                            &one, &one);
+            }
+
+            break;
+
+        case PA_SAMPLE_S16NE:
+
+            for (oc = 0; oc < r->o_ss.channels; oc++) {
+                unsigned i;
+                static const int16_t one = 1;
+
+                for (i = 0; i < PA_CHANNELS_MAX && r->map_table[oc][i] >= 0; i++)
+                    oil_vectoradd_s16(
+                            (int16_t*) dst + oc, o_skip,
+                            (int16_t*) dst + oc, o_skip,
+                            (int16_t*) src + r->map_table[oc][i], i_skip,
+                            n_frames,
+                            &one, &one);
+            }
+
+            break;
+
+        default:
+            pa_assert_not_reached();
     }
 
-    return u->buf2;
+    pa_memblock_release(input->memblock);
+    pa_memblock_release(r->buf2.memblock);
+
+    r->buf2.length = out_n_samples * r->w_sz;
+
+    return &r->buf2;
 }
 
-static float *resample(pa_resampler *r, float *input, unsigned *n_frames) {
-    struct impl_libsamplerate *u;
-    SRC_DATA data;
+static pa_memchunk *resample(pa_resampler *r, pa_memchunk *input) {
+    unsigned in_n_frames, in_n_samples;
     unsigned out_n_frames, out_n_samples;
-    int ret;
 
-    assert(r);
-    assert(input);
-    assert(n_frames);
-    assert(r->impl_data);
-    u = r->impl_data;
+    pa_assert(r);
+    pa_assert(input);
 
     /* Resample the data and place the result in buf3 */
 
-    if (!u->src_state)
+    if (!r->impl_resample || !input->length)
         return input;
 
-    out_n_frames = (*n_frames*r->o_ss.rate/r->i_ss.rate)+1024;
+    in_n_samples = input->length / r->w_sz;
+    in_n_frames = in_n_samples / r->o_ss.channels;
+
+    out_n_frames = ((in_n_frames*r->o_ss.rate)/r->i_ss.rate)+EXTRA_SAMPLES;
     out_n_samples = out_n_frames * r->o_ss.channels;
 
-    if (u->buf3_samples < out_n_samples) {
-        if (u->buf3_block)
-            pa_memblock_unref(u->buf3_block);
+    r->buf3.index = 0;
+    r->buf3.length = r->w_sz * out_n_samples;
+
+    if (!r->buf3.memblock || r->buf3_samples < out_n_samples) {
+        if (r->buf3.memblock)
+            pa_memblock_unref(r->buf3.memblock);
 
-        u->buf3_samples = out_n_samples;
-        u->buf3_block = pa_memblock_new(r->mempool, sizeof(float) * out_n_samples);
-        u->buf3 = u->buf3_block->data;
+        r->buf3_samples = out_n_samples;
+        r->buf3.memblock = pa_memblock_new(r->mempool, r->buf3.length);
     }
 
-    data.data_in = input;
-    data.input_frames = *n_frames;
+    r->impl_resample(r, input, in_n_frames, &r->buf3, &out_n_frames);
+    r->buf3.length = out_n_frames * r->w_sz * r->o_ss.channels;
 
-    data.data_out = u->buf3;
-    data.output_frames = out_n_frames;
+    return &r->buf3;
+}
 
-    data.src_ratio = (double) r->o_ss.rate / r->i_ss.rate;
-    data.end_of_input = 0;
+static pa_memchunk *convert_from_work_format(pa_resampler *r, pa_memchunk *input) {
+    unsigned n_samples, n_frames;
+    void *src, *dst;
+
+    pa_assert(r);
+    pa_assert(input);
+
+    /* Convert the data into the correct sample type and place the result in buf4 */
+
+    if (!r->from_work_format_func || !input->length)
+        return input;
+
+    n_samples = input->length / r->w_sz;
+    n_frames =  n_samples / r->o_ss.channels;
+
+    r->buf4.index = 0;
+    r->buf4.length = r->o_fz * n_frames;
+
+    if (!r->buf4.memblock || r->buf4_samples < n_samples) {
+        if (r->buf4.memblock)
+            pa_memblock_unref(r->buf4.memblock);
+
+        r->buf4_samples = n_samples;
+        r->buf4.memblock = pa_memblock_new(r->mempool, r->buf4.length);
+    }
 
-    ret = src_process(u->src_state, &data);
-    assert(ret == 0);
-    assert((unsigned) data.input_frames_used == *n_frames);
+    src = (uint8_t*) pa_memblock_acquire(input->memblock) + input->index;
+    dst = pa_memblock_acquire(r->buf4.memblock);
+    r->from_work_format_func(n_samples, src, dst);
+    pa_memblock_release(input->memblock);
+    pa_memblock_release(r->buf4.memblock);
 
-    *n_frames = data.output_frames_gen;
+    r->buf4.length = r->o_fz * n_frames;
 
-    return u->buf3;
+    return &r->buf4;
 }
 
-static void *convert_from_float(pa_resampler *r, float *input, unsigned n_frames) {
-    struct impl_libsamplerate *u;
-    unsigned n_samples;
+void pa_resampler_run(pa_resampler *r, const pa_memchunk *in, pa_memchunk *out) {
+    pa_memchunk *buf;
+
+    pa_assert(r);
+    pa_assert(in);
+    pa_assert(out);
+    pa_assert(in->length);
+    pa_assert(in->memblock);
+    pa_assert(in->length % r->i_fz == 0);
+
+    buf = (pa_memchunk*) in;
+    buf = convert_to_work_format(r, buf);
+    buf = remap_channels(r, buf);
+    buf = resample(r, buf);
+
+    if (buf->length) {
+        buf = convert_from_work_format(r, buf);
+        *out = *buf;
+
+        if (buf == in)
+            pa_memblock_ref(buf->memblock);
+        else
+            pa_memchunk_reset(buf);
+    } else
+        pa_memchunk_reset(out);
+}
 
-    assert(r);
-    assert(input);
-    assert(r->impl_data);
-    u = r->impl_data;
+/*** libsamplerate based implementation ***/
 
-    /* Convert the data into the correct sample type and place the result in buf4 */
+#ifdef HAVE_LIBSAMPLERATE
+static void libsamplerate_resample(pa_resampler *r, const pa_memchunk *input, unsigned in_n_frames, pa_memchunk *output, unsigned *out_n_frames) {
+    SRC_DATA data;
 
-    if (!u->from_float32ne_func)
-        return input;
+    pa_assert(r);
+    pa_assert(input);
+    pa_assert(output);
+    pa_assert(out_n_frames);
 
-    n_samples = n_frames * r->o_ss.channels;
+    memset(&data, 0, sizeof(data));
 
-    if (u->buf4_samples < n_samples) {
-        if (u->buf4_block)
-            pa_memblock_unref(u->buf4_block);
+    data.data_in = (float*) ((uint8_t*) pa_memblock_acquire(input->memblock) + input->index);
+    data.input_frames = in_n_frames;
 
-        u->buf4_samples = n_samples;
-        u->buf4_block = pa_memblock_new(r->mempool, sizeof(float) * n_samples);
-        u->buf4 = u->buf4_block->data;
-    }
+    data.data_out = (float*) ((uint8_t*) pa_memblock_acquire(output->memblock) + output->index);
+    data.output_frames = *out_n_frames;
 
-    u->from_float32ne_func(n_samples, input, u->buf4);
-
-    return u->buf4;
-}
-
-static void libsamplerate_run(pa_resampler *r, const pa_memchunk *in, pa_memchunk *out) {
-    struct impl_libsamplerate *u;
-    float *buf;
-    void *input, *output;
-    unsigned n_frames;
-
-    assert(r);
-    assert(in);
-    assert(out);
-    assert(in->length);
-    assert(in->memblock);
-    assert(in->length % r->i_fz == 0);
-    assert(r->impl_data);
-
-    u = r->impl_data;
-
-    input = ((uint8_t*) in->memblock->data + in->index);
-    n_frames = in->length / r->i_fz;
-    assert(n_frames > 0);
-
-    buf = convert_to_float(r, input, n_frames);
-    buf = remap_channels(r, buf, n_frames);
-    buf = resample(r, buf, &n_frames);
-
-    if (n_frames) {
-        output = convert_from_float(r, buf, n_frames);
-
-        if (output == input) {
-            /* Mm, no adjustment has been necessary, so let's return the original block */
-            out->memblock = pa_memblock_ref(in->memblock);
-            out->index = in->index;
-            out->length = in->length;
-        } else {
-            out->length = n_frames * r->o_fz;
-            out->index = 0;
-            out->memblock = NULL;
-
-            if (output == u->buf1) {
-                u->buf1 = NULL;
-                u->buf1_samples = 0;
-                out->memblock = u->buf1_block;
-                u->buf1_block = NULL;
-            } else if (output == u->buf2) {
-                u->buf2 = NULL;
-                u->buf2_samples = 0;
-                out->memblock = u->buf2_block;
-                u->buf2_block = NULL;
-            } else if (output == u->buf3) {
-                u->buf3 = NULL;
-                u->buf3_samples = 0;
-                out->memblock = u->buf3_block;
-                u->buf3_block = NULL;
-            } else if (output == u->buf4) {
-                u->buf4 = NULL;
-                u->buf4_samples = 0;
-                out->memblock = u->buf4_block;
-                u->buf4_block = NULL;
-            }
+    data.src_ratio = (double) r->o_ss.rate / r->i_ss.rate;
+    data.end_of_input = 0;
 
-            assert(out->memblock);
-        }
-    } else {
-        out->memblock = NULL;
-        out->index = out->length = 0;
-    }
+    pa_assert_se(src_process(r->src.state, &data) == 0);
+    pa_assert((unsigned) data.input_frames_used == in_n_frames);
+
+    pa_memblock_release(input->memblock);
+    pa_memblock_release(output->memblock);
+
+    *out_n_frames = data.output_frames_gen;
 }
 
-static void libsamplerate_update_input_rate(pa_resampler *r, uint32_t rate) {
-    struct impl_libsamplerate *u;
+static void libsamplerate_update_rates(pa_resampler *r) {
+    pa_assert(r);
 
-    assert(r);
-    assert(rate > 0);
-    assert(r->impl_data);
-    u = r->impl_data;
+    pa_assert_se(src_set_ratio(r->src.state, (double) r->o_ss.rate / r->i_ss.rate) == 0);
+}
 
-    if (!u->src_state) {
-        int err;
-        u->src_state = src_new(r->resample_method, r->o_ss.channels, &err);
-        assert(u->src_state);
-    } else {
-        int ret = src_set_ratio(u->src_state, (double) r->o_ss.rate / rate);
-        assert(ret == 0);
-    }
+static void libsamplerate_free(pa_resampler *r) {
+    pa_assert(r);
+
+    if (r->src.state)
+        src_delete(r->src.state);
 }
 
 static int libsamplerate_init(pa_resampler *r) {
-    struct impl_libsamplerate *u = NULL;
     int err;
 
-    r->impl_data = u = pa_xnew(struct impl_libsamplerate, 1);
+    pa_assert(r);
 
-    u->buf1 = u->buf2 = u->buf3 = u->buf4 = NULL;
-    u->buf1_block = u->buf2_block = u->buf3_block = u->buf4_block = NULL;
-    u->buf1_samples = u->buf2_samples = u->buf3_samples = u->buf4_samples = 0;
+    if (!(r->src.state = src_new(r->resample_method, r->o_ss.channels, &err)))
+        return -1;
 
-    if (r->i_ss.format == PA_SAMPLE_FLOAT32NE)
-        u->to_float32ne_func = NULL;
-    else if (!(u->to_float32ne_func = pa_get_convert_to_float32ne_function(r->i_ss.format)))
-        goto fail;
+    r->impl_free = libsamplerate_free;
+    r->impl_update_rates = libsamplerate_update_rates;
+    r->impl_resample = libsamplerate_resample;
 
-    if (r->o_ss.format == PA_SAMPLE_FLOAT32NE)
-        u->from_float32ne_func = NULL;
-    else if (!(u->from_float32ne_func = pa_get_convert_from_float32ne_function(r->o_ss.format)))
-        goto fail;
+    return 0;
+}
+#endif
 
-    if (r->o_ss.rate == r->i_ss.rate)
-        u->src_state = NULL;
-    else if (!(u->src_state = src_new(r->resample_method, r->o_ss.channels, &err)))
-        goto fail;
+/*** speex based implementation ***/
 
-    r->impl_free = libsamplerate_free;
-    r->impl_update_input_rate = libsamplerate_update_input_rate;
-    r->impl_run = libsamplerate_run;
+static void speex_resample_float(pa_resampler *r, const pa_memchunk *input, unsigned in_n_frames, pa_memchunk *output, unsigned *out_n_frames) {
+    float *in, *out;
+    uint32_t inf = in_n_frames, outf = *out_n_frames;
 
-    calc_map_table(r);
+    pa_assert(r);
+    pa_assert(input);
+    pa_assert(output);
+    pa_assert(out_n_frames);
 
-    return 0;
+    in = (float*) ((uint8_t*) pa_memblock_acquire(input->memblock) + input->index);
+    out = (float*) ((uint8_t*) pa_memblock_acquire(output->memblock) + output->index);
 
-fail:
-    pa_xfree(u);
-    return -1;
+    pa_assert_se(paspfl_resampler_process_interleaved_float(r->speex.state, in, &inf, out, &outf) == 0);
+
+    pa_memblock_release(input->memblock);
+    pa_memblock_release(output->memblock);
+
+    pa_assert(inf == in_n_frames);
+    *out_n_frames = outf;
 }
 
-/* Trivial implementation */
+static void speex_resample_int(pa_resampler *r, const pa_memchunk *input, unsigned in_n_frames, pa_memchunk *output, unsigned *out_n_frames) {
+    int16_t *in, *out;
+    uint32_t inf = in_n_frames, outf = *out_n_frames;
 
-static void trivial_run(pa_resampler *r, const pa_memchunk *in, pa_memchunk *out) {
-    size_t fz;
-    unsigned  n_frames;
-    struct impl_trivial *u;
+    pa_assert(r);
+    pa_assert(input);
+    pa_assert(output);
+    pa_assert(out_n_frames);
+
+    in = (int16_t*) ((uint8_t*) pa_memblock_acquire(input->memblock) + input->index);
+    out = (int16_t*) ((uint8_t*) pa_memblock_acquire(output->memblock) + output->index);
+
+    pa_assert_se(paspfx_resampler_process_interleaved_int(r->speex.state, in, &inf, out, &outf) == 0);
+
+    pa_memblock_release(input->memblock);
+    pa_memblock_release(output->memblock);
 
-    assert(r);
-    assert(in);
-    assert(out);
-    assert(r->impl_data);
+    pa_assert(inf == in_n_frames);
+    *out_n_frames = outf;
+}
 
-    u = r->impl_data;
+static void speex_update_rates(pa_resampler *r) {
+    pa_assert(r);
 
-    fz = r->i_fz;
-    assert(fz == r->o_fz);
+    if (r->resample_method >= PA_RESAMPLER_SPEEX_FIXED_BASE && r->resample_method <= PA_RESAMPLER_SPEEX_FIXED_MAX)
+        pa_assert_se(paspfx_resampler_set_rate(r->speex.state, r->i_ss.rate, r->o_ss.rate) == 0);
+    else {
+        pa_assert(r->resample_method >= PA_RESAMPLER_SPEEX_FLOAT_BASE && r->resample_method <= PA_RESAMPLER_SPEEX_FLOAT_MAX);
+        pa_assert_se(paspfl_resampler_set_rate(r->speex.state, r->i_ss.rate, r->o_ss.rate) == 0);
+    }
+}
 
-    n_frames = in->length/fz;
+static void speex_free(pa_resampler *r) {
+    pa_assert(r);
 
-    if (r->i_ss.rate == r->o_ss.rate) {
+    if (!r->speex.state)
+        return;
+
+    if (r->resample_method >= PA_RESAMPLER_SPEEX_FIXED_BASE && r->resample_method <= PA_RESAMPLER_SPEEX_FIXED_MAX)
+        paspfx_resampler_destroy(r->speex.state);
+    else {
+        pa_assert(r->resample_method >= PA_RESAMPLER_SPEEX_FLOAT_BASE && r->resample_method <= PA_RESAMPLER_SPEEX_FLOAT_MAX);
+        paspfl_resampler_destroy(r->speex.state);
+    }
+}
 
-        /* In case there's no diefference in sample types, do nothing */
-        *out = *in;
-        pa_memblock_ref(out->memblock);
+static int speex_init(pa_resampler *r) {
+    int q, err;
 
-        u->o_counter += n_frames;
+    pa_assert(r);
+
+    r->impl_free = speex_free;
+    r->impl_update_rates = speex_update_rates;
+
+    if (r->resample_method >= PA_RESAMPLER_SPEEX_FIXED_BASE && r->resample_method <= PA_RESAMPLER_SPEEX_FIXED_MAX) {
+        q = r->resample_method - PA_RESAMPLER_SPEEX_FIXED_BASE;
+
+        pa_log_info("Choosing speex quality setting %i.", q);
+
+        if (!(r->speex.state = paspfx_resampler_init(r->o_ss.channels, r->i_ss.rate, r->o_ss.rate, q, &err)))
+            return -1;
+
+        r->impl_resample = speex_resample_int;
     } else {
-        /* Do real resampling */
-        size_t l;
-        unsigned o_index;
+        pa_assert(r->resample_method >= PA_RESAMPLER_SPEEX_FLOAT_BASE && r->resample_method <= PA_RESAMPLER_SPEEX_FLOAT_MAX);
+        q = r->resample_method - PA_RESAMPLER_SPEEX_FLOAT_BASE;
+
+        pa_log_info("Choosing speex quality setting %i.", q);
 
-        /* The length of the new memory block rounded up */
-        l = ((((n_frames+1) * r->o_ss.rate) / r->i_ss.rate) + 1) * fz;
+        if (!(r->speex.state = paspfl_resampler_init(r->o_ss.channels, r->i_ss.rate, r->o_ss.rate, q, &err)))
+            return -1;
 
-        out->index = 0;
-        out->memblock = pa_memblock_new(r->mempool, l);
+        r->impl_resample = speex_resample_float;
+    }
 
-        for (o_index = 0;; o_index++, u->o_counter++) {
-            unsigned j;
+    return 0;
+}
 
-            j = (u->o_counter * r->i_ss.rate / r->o_ss.rate);
-            j = j > u->i_counter ? j - u->i_counter : 0;
+/* Trivial implementation */
 
-            if (j >= n_frames)
-                break;
+static void trivial_resample(pa_resampler *r, const pa_memchunk *input, unsigned in_n_frames, pa_memchunk *output, unsigned *out_n_frames) {
+    size_t fz;
+    unsigned o_index;
+    void *src, *dst;
 
-            assert(o_index*fz < out->memblock->length);
+    pa_assert(r);
+    pa_assert(input);
+    pa_assert(output);
+    pa_assert(out_n_frames);
 
-            memcpy((uint8_t*) out->memblock->data + fz*o_index,
-                   (uint8_t*) in->memblock->data + in->index + fz*j, fz);
+    fz = r->w_sz * r->o_ss.channels;
 
-        }
+    src = (uint8_t*) pa_memblock_acquire(input->memblock) + input->index;
+    dst = (uint8_t*) pa_memblock_acquire(output->memblock) + output->index;
+
+    for (o_index = 0;; o_index++, r->trivial.o_counter++) {
+        unsigned j;
 
-        out->length = o_index*fz;
+        j = ((r->trivial.o_counter * r->i_ss.rate) / r->o_ss.rate);
+        j = j > r->trivial.i_counter ? j - r->trivial.i_counter : 0;
+
+        if (j >= in_n_frames)
+            break;
+
+        pa_assert(o_index * fz < pa_memblock_get_length(output->memblock));
+
+        oil_memcpy((uint8_t*) dst + fz * o_index,
+                   (uint8_t*) src + fz * j, fz);
     }
 
-    u->i_counter += n_frames;
+    pa_memblock_release(input->memblock);
+    pa_memblock_release(output->memblock);
+
+    *out_n_frames = o_index;
+
+    r->trivial.i_counter += in_n_frames;
 
     /* Normalize counters */
-    while (u->i_counter >= r->i_ss.rate) {
-        u->i_counter -= r->i_ss.rate;
-        assert(u->o_counter >= r->o_ss.rate);
-        u->o_counter -= r->o_ss.rate;
+    while (r->trivial.i_counter >= r->i_ss.rate) {
+        pa_assert(r->trivial.o_counter >= r->o_ss.rate);
+
+        r->trivial.i_counter -= r->i_ss.rate;
+        r->trivial.o_counter -= r->o_ss.rate;
     }
 }
 
-static void trivial_free(pa_resampler *r) {
-    assert(r);
+static void trivial_update_rates(pa_resampler *r) {
+    pa_assert(r);
 
-    pa_xfree(r->impl_data);
+    r->trivial.i_counter = 0;
+    r->trivial.o_counter = 0;
 }
 
-static void trivial_update_input_rate(pa_resampler *r, uint32_t rate) {
-    struct impl_trivial *u;
+static int trivial_init(pa_resampler*r) {
+    pa_assert(r);
+
+    r->trivial.o_counter = r->trivial.i_counter = 0;
 
-    assert(r);
-    assert(rate > 0);
-    assert(r->impl_data);
+    r->impl_resample = trivial_resample;
+    r->impl_update_rates = trivial_update_rates;
+    r->impl_free = NULL;
 
-    u = r->impl_data;
-    u->i_counter = 0;
-    u->o_counter = 0;
+    return 0;
 }
 
-static int trivial_init(pa_resampler*r) {
-    struct impl_trivial *u;
+/*** ffmpeg based implementation ***/
+
+static void 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;
+
+    pa_assert(r);
+    pa_assert(input);
+    pa_assert(output);
+    pa_assert(out_n_frames);
+
+    for (c = 0; c < r->o_ss.channels; c++) {
+        unsigned u;
+        pa_memblock *b, *w;
+        int16_t *p, *t, *k, *q, *s;
+        int consumed_frames;
+        unsigned in, l;
+
+        /* Allocate a new block */
+        b = pa_memblock_new(r->mempool, r->ffmpeg.buf[c].length + in_n_frames * sizeof(int16_t));
+        p = pa_memblock_acquire(b);
+
+        /* Copy the remaining data into it */
+        l = r->ffmpeg.buf[c].length;
+        if (r->ffmpeg.buf[c].memblock) {
+            t = (int16_t*) ((uint8_t*) pa_memblock_acquire(r->ffmpeg.buf[c].memblock) + r->ffmpeg.buf[c].index);
+            memcpy(p, t, l);
+            pa_memblock_release(r->ffmpeg.buf[c].memblock);
+            pa_memblock_unref(r->ffmpeg.buf[c].memblock);
+            pa_memchunk_reset(&r->ffmpeg.buf[c]);
+        }
+
+        /* Now append the new data, splitting up channels */
+        t = ((int16_t*) ((uint8_t*) pa_memblock_acquire(input->memblock) + input->index)) + c;
+        k = (int16_t*) ((uint8_t*) p + l);
+        for (u = 0; u < in_n_frames; u++) {
+            *k = *t;
+            t += r->o_ss.channels;
+            k ++;
+        }
+        pa_memblock_release(input->memblock);
+
+        /* Calculate the resulting number of frames */
+        in = in_n_frames + l / sizeof(int16_t);
+
+        /* 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 = av_resample(r->ffmpeg.state,
+                                  q, p,
+                                  &consumed_frames,
+                                  in, *out_n_frames,
+                                  c >= (unsigned) r->o_ss.channels-1);
+
+        pa_memblock_release(b);
+
+        /* Now store the remaining samples away */
+        pa_assert(consumed_frames <= (int) in);
+        if (consumed_frames < (int) in) {
+            r->ffmpeg.buf[c].memblock = b;
+            r->ffmpeg.buf[c].index = consumed_frames * sizeof(int16_t);
+            r->ffmpeg.buf[c].length = (in - consumed_frames) * sizeof(int16_t);
+        } else
+            pa_memblock_unref(b);
+
+        /* And place the results in the output buffer */
+        s = (short*) ((uint8_t*) pa_memblock_acquire(output->memblock) + output->index) + c;
+        for (u = 0; u < used_frames; u++) {
+            *s = *q;
+            q++;
+            s += r->o_ss.channels;
+        }
+        pa_memblock_release(output->memblock);
+        pa_memblock_release(w);
+        pa_memblock_unref(w);
+    }
+
+    *out_n_frames = used_frames;
+}
+
+static void ffmpeg_free(pa_resampler *r) {
+    unsigned c;
 
-    assert(r);
-    assert(r->i_ss.format == r->o_ss.format);
-    assert(r->i_ss.channels == r->o_ss.channels);
+    pa_assert(r);
 
-    r->impl_data = u = pa_xnew(struct impl_trivial, 1);
-    u->o_counter = u->i_counter = 0;
+    if (r->ffmpeg.state)
+        av_resample_close(r->ffmpeg.state);
 
-    r->impl_run = trivial_run;
-    r->impl_free = trivial_free;
-    r->impl_update_input_rate = trivial_update_input_rate;
+    for (c = 0; c < PA_ELEMENTSOF(r->ffmpeg.buf); c++)
+        if (r->ffmpeg.buf[c].memblock)
+            pa_memblock_unref(r->ffmpeg.buf[c].memblock);
+}
+
+static int ffmpeg_init(pa_resampler *r) {
+    unsigned c;
+
+    pa_assert(r);
+
+    /* 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 (!(r->ffmpeg.state = av_resample_init(r->o_ss.rate, r->i_ss.rate, 16, 10, 0, 0.8)))
+        return -1;
+
+    r->impl_free = ffmpeg_free;
+    r->impl_resample = ffmpeg_resample;
+
+    for (c = 0; c < PA_ELEMENTSOF(r->ffmpeg.buf); c++)
+        pa_memchunk_reset(&r->ffmpeg.buf[c]);
 
     return 0;
 }
 
+/*** copy (noop) implementation ***/
 
+static int copy_init(pa_resampler *r) {
+    pa_assert(r);
+
+    pa_assert(r->o_ss.rate == r->i_ss.rate);
+
+    r->impl_free = NULL;
+    r->impl_resample = NULL;
+    r->impl_update_rates = NULL;
+
+    return 0;
+}