Use pw_buffer::requested in newer PipeWire versions

1 files changed, 26 insertions, 16 deletions

diff --git a/alc/backends/pipewire.cpp b/alc/backends/pipewire.cpp
index b573bd5a..165579b2 100644
--- a/alc/backends/pipewire.cpp
+++ b/alc/backends/pipewire.cpp
@@ -1308,32 +1308,42 @@ void PipeWirePlayback::outputCallback()
     pw_buffer *pw_buf{pw_stream_dequeue_buffer(mStream.get())};
     if(unlikely(!pw_buf)) return;
 
+    const al::span<spa_data> datas{pw_buf->buffer->datas,
+        minu(mNumChannels, pw_buf->buffer->n_datas)};
+#if PW_CHECK_VERSION(0,3,49)
+    /* In 0.3.49, pw_buffer::requested specifies the number of samples needed
+     * by the resampler/graph for this audio update.
+     */
+    uint length{static_cast<uint>(pw_buf->requested)};
+#else
+    /* In 0.3.48 and earlier, spa_io_rate_match::size apparently has the number
+     * of samples per update.
+     */
+    uint length{mRateMatch ? mRateMatch->size : 0u};
+#endif
+    /* If no length is specified, use the device's update size as a fallback. */
+    if(unlikely(!length)) length = mDevice->UpdateSize;
+
     /* For planar formats, each datas[] seems to contain one channel, so store
      * the pointers in an array. Limit the render length in case the available
      * buffer length in any one channel is smaller than we wanted (shouldn't
      * be, but just in case).
      */
-    spa_data *datas{pw_buf->buffer->datas};
-    const size_t chancount{minu(mNumChannels, pw_buf->buffer->n_datas)};
-    /* TODO: How many samples should actually be written? 'maxsize' can be 16k
-     * samples, which is excessive (~341ms @ 48khz). SPA_IO_RateMatch contains
-     * a 'size' field that apparently indicates how many samples should be
-     * written per update, but it's not obviously right.
-     */
-    uint length{mRateMatch ? mRateMatch->size : mDevice->UpdateSize};
-    for(size_t i{0};i < chancount;++i)
+    float **chanptr_end{mChannelPtrs.get()};
+    for(const auto &data : datas)
     {
-        length = minu(length, datas[i].maxsize/sizeof(float));
-        mChannelPtrs[i] = static_cast<float*>(datas[i].data);
+        length = minu(length, data.maxsize/sizeof(float));
+        *chanptr_end = static_cast<float*>(data.data);
+        ++chanptr_end;
     }
 
-    mDevice->renderSamples({mChannelPtrs.get(), chancount}, length);
+    mDevice->renderSamples({mChannelPtrs.get(), chanptr_end}, length);
 
-    for(size_t i{0};i < chancount;++i)
+    for(const auto &data : datas)
     {
-        datas[i].chunk->offset = 0;
-        datas[i].chunk->stride = sizeof(float);
-        datas[i].chunk->size   = length * sizeof(float);
+        data.chunk->offset = 0;
+        data.chunk->stride = sizeof(float);
+        data.chunk->size   = length * sizeof(float);
     }
     pw_buf->size = length;
     pw_stream_queue_buffer(mStream.get(), pw_buf);