From c329a41dd3d25f6646136fe3be11edf37dc451bc Mon Sep 17 00:00:00 2001
From: rdb <git@rdb.name>
Date: Mon, 29 Apr 2019 18:00:29 +0200
Subject: [PATCH] movies: Python-facing read_samples should return bytes object

Also, properly returns partial buffers based on number of actual samples read
---
 panda/src/movies/movieAudioCursor.cxx | 27 ++++++++++++++++-----------
 panda/src/movies/movieAudioCursor.h   |  2 +-
 2 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/panda/src/movies/movieAudioCursor.cxx b/panda/src/movies/movieAudioCursor.cxx
index a725b56ad1..a836937455 100644
--- a/panda/src/movies/movieAudioCursor.cxx
+++ b/panda/src/movies/movieAudioCursor.cxx
@@ -93,23 +93,28 @@ read_samples(int n, Datagram *dg) {
  * This is not particularly efficient, but it may be a convenient way to
  * manipulate samples in python.
  */
-std::string MovieAudioCursor::
+vector_uchar MovieAudioCursor::
 read_samples(int n) {
-  std::ostringstream result;
+  vector_uchar result;
   int16_t tmp[4096];
   while (n > 0) {
     int blocksize = (4096 / _audio_channels);
-    if (blocksize > n) blocksize = n;
-    int words = blocksize * _audio_channels;
-    read_samples(blocksize, tmp);
-    for (int i=0; i<words; i++) {
-      int16_t word = tmp[i];
-      result.put((char)(word & 255));
-      result.put((char)((word>>8) & 255));
+    if (blocksize > n) {
+      blocksize = n;
     }
-    n -= blocksize;
+    int nread = read_samples(blocksize, tmp);
+    if (nread == 0) {
+      return result;
+    }
+    int words = nread * _audio_channels;
+    for (int i = 0; i < words; ++i) {
+      int16_t word = tmp[i];
+      result.push_back((uint8_t)(word & 255u));
+      result.push_back((uint8_t)((word >> 8) & 255u));
+    }
+    n -= nread;
   }
-  return result.str();
+  return result;
 }
 
 
diff --git a/panda/src/movies/movieAudioCursor.h b/panda/src/movies/movieAudioCursor.h
index 28674f1215..e7c9668713 100644
--- a/panda/src/movies/movieAudioCursor.h
+++ b/panda/src/movies/movieAudioCursor.h
@@ -48,7 +48,7 @@ PUBLISHED:
   virtual int ready() const;
   virtual void seek(double offset);
   void read_samples(int n, Datagram *dg);
-  std::string read_samples(int n);
+  vector_uchar read_samples(int n);
 
 public:
   virtual int read_samples(int n, int16_t *data);