[PATCH 09/11] resampler: Extend fit_buf() helper to copy leftover data to new buffer

[pmeerw@xxxxxxxxxx (Peter Meerwald)]

Signed-off-by: Peter Meerwald <pmeerw at pmeerw.net>
---
 src/pulsecore/resampler.c | 40 +++++++++++++++++++---------------------
 1 file changed, 19 insertions(+), 21 deletions(-)

diff --git a/src/pulsecore/resampler.c b/src/pulsecore/resampler.c
index 2cbcc52..3cb4e8a 100644
--- a/src/pulsecore/resampler.c
+++ b/src/pulsecore/resampler.c
@@ -1029,13 +1029,26 @@ static void calc_map_table(pa_resampler *r) {
     pa_init_remap(m);
 }
 
-static size_t fit_buf(pa_resampler *r, pa_memchunk *buf, size_t size) {
+/* check if buf's memblock is large enough to hold 'size' bytes; create a
+ * new memblock if necessary and optionally preserve 'copy' data bytes */
+static size_t fit_buf(pa_resampler *r, pa_memchunk *buf, size_t size, size_t copy) {
     if (!buf->memblock || size < buf->length) {
         size = buf->length;
+        pa_memblock *new_block = pa_memblock_new(r->mempool, size);
+
+        if (copy > 0) {
+            void *src = pa_memblock_acquire(buf->memblock);
+            void *dst = pa_memblock_acquire(new_block);
+            pa_assert(copy <= size);
+            memcpy(dst, src, copy);
+            pa_memblock_release(new_block);
+            pa_memblock_release(buf->memblock);
+        }
+
         if (buf->memblock)
             pa_memblock_unref(buf->memblock);
 
-        buf->memblock = pa_memblock_new(r->mempool, size);
+        buf->memblock = new_block;
     }
     return size;
 }
@@ -1103,22 +1116,7 @@ static pa_memchunk *remap_channels(pa_resampler *r, pa_memchunk *input) {
     out_n_samples = out_n_frames * r->o_ss.channels;
     r->remap_buf.length = out_n_samples * r->w_sz;
 
-    if (have_leftover) {
-        if (r->remap_buf_size < r->remap_buf.length) {
-            pa_memblock *new_block = pa_memblock_new(r->mempool, r->remap_buf.length);
-
-            src = pa_memblock_acquire(r->remap_buf.memblock);
-            dst = pa_memblock_acquire(new_block);
-            memcpy(dst, src, leftover_length);
-            pa_memblock_release(r->remap_buf.memblock);
-            pa_memblock_release(new_block);
-
-            pa_memblock_unref(r->remap_buf.memblock);
-            r->remap_buf.memblock = new_block;
-            r->remap_buf_size = r->remap_buf.length;
-        }
-    } else
-        r->remap_buf_size = fit_buf(r, &r->remap_buf, r->remap_buf_size);
+    r->remap_buf_size = fit_buf(r, &r->remap_buf, r->remap_buf_size, leftover_length);
 
     src = pa_memblock_acquire_chunk(input);
     dst = (uint8_t *) pa_memblock_acquire(r->remap_buf.memblock) + leftover_length;
@@ -1147,7 +1145,7 @@ static void save_leftover(pa_resampler *r, void *buf, size_t len) {
 
     /* Store the leftover data. */
     r->leftover_buf->length = len;
-    *r->leftover_buf_size = fit_buf(r, r->leftover_buf, *r->leftover_buf_size);
+    *r->leftover_buf_size = fit_buf(r, r->leftover_buf, *r->leftover_buf_size, 0);
     *r->have_leftover = true;
 
     dst = pa_memblock_acquire(r->leftover_buf->memblock);
@@ -1171,7 +1169,7 @@ static pa_memchunk *resample(pa_resampler *r, pa_memchunk *input) {
     out_n_frames = ((in_n_frames*r->o_ss.rate)/r->i_ss.rate)+EXTRA_FRAMES;
 
     r->resample_buf.length = r->w_fz * out_n_frames;
-    r->resample_buf_size = fit_buf(r, &r->resample_buf, r->resample_buf_size);
+    r->resample_buf_size = fit_buf(r, &r->resample_buf, r->resample_buf_size, 0);
 
     leftover_n_frames = r->impl_resample(r, input, in_n_frames, &r->resample_buf, &out_n_frames);
     if (leftover_n_frames > 0) {
@@ -1202,7 +1200,7 @@ static pa_memchunk *convert_from_work_format(pa_resampler *r, pa_memchunk *input
     n_frames = n_samples / r->o_ss.channels;
 
     r->from_work_format_buf.length = r->o_fz * n_frames;
-    r->from_work_format_buf_size = fit_buf(r, &r->from_work_format_buf, r->from_work_format_buf_size);
+    r->from_work_format_buf_size = fit_buf(r, &r->from_work_format_buf, r->from_work_format_buf_size, 0);
 
     src = pa_memblock_acquire_chunk(input);
     dst = pa_memblock_acquire(r->from_work_format_buf.memblock);
-- 
1.8.3.2