From c513342247db5e0c54f696ccc4f78bd0fe3cac24 Mon Sep 17 00:00:00 2001
From: rdb <git@rdb.name>
Date: Mon, 29 Apr 2019 17:55:15 +0200
Subject: [PATCH] movies: return actual number of samples read in read_samples

Various codecs may only partially fill the buffer and fill the rest with zeroes, but it is useful to know how many samples were actually read.
---
 panda/src/ffmpeg/ffmpegAudioCursor.cxx   | 3 ++-
 panda/src/ffmpeg/ffmpegAudioCursor.h     | 2 +-
 panda/src/movies/flacAudioCursor.cxx     | 6 ++++--
 panda/src/movies/flacAudioCursor.h       | 2 +-
 panda/src/movies/microphoneAudioDS.cxx   | 5 +++--
 panda/src/movies/movieAudioCursor.cxx    | 5 +++--
 panda/src/movies/movieAudioCursor.h      | 2 +-
 panda/src/movies/opusAudioCursor.cxx     | 4 +++-
 panda/src/movies/opusAudioCursor.h       | 2 +-
 panda/src/movies/userDataAudio.cxx       | 9 ++++++---
 panda/src/movies/userDataAudio.h         | 2 +-
 panda/src/movies/userDataAudioCursor.cxx | 9 ++++++---
 panda/src/movies/userDataAudioCursor.h   | 2 +-
 panda/src/movies/vorbisAudioCursor.cxx   | 3 ++-
 panda/src/movies/vorbisAudioCursor.h     | 2 +-
 panda/src/movies/wavAudioCursor.cxx      | 8 +++++---
 panda/src/movies/wavAudioCursor.h        | 2 +-
 17 files changed, 42 insertions(+), 26 deletions(-)

diff --git a/panda/src/ffmpeg/ffmpegAudioCursor.cxx b/panda/src/ffmpeg/ffmpegAudioCursor.cxx
index 4b17800c2b..2fdc10b983 100644
--- a/panda/src/ffmpeg/ffmpegAudioCursor.cxx
+++ b/panda/src/ffmpeg/ffmpegAudioCursor.cxx
@@ -462,7 +462,7 @@ seek(double t) {
  * read.  Your buffer must be equal in size to N * channels.  Multiple-channel
  * audio will be interleaved.
  */
-void FfmpegAudioCursor::
+int FfmpegAudioCursor::
 read_samples(int n, int16_t *data) {
   int desired = n * _audio_channels;
 
@@ -486,4 +486,5 @@ read_samples(int n, int16_t *data) {
 
   }
   _samples_read += n;
+  return n;
 }
diff --git a/panda/src/ffmpeg/ffmpegAudioCursor.h b/panda/src/ffmpeg/ffmpegAudioCursor.h
index f3963ff527..77e8890d6c 100644
--- a/panda/src/ffmpeg/ffmpegAudioCursor.h
+++ b/panda/src/ffmpeg/ffmpegAudioCursor.h
@@ -45,7 +45,7 @@ PUBLISHED:
   virtual void seek(double offset);
 
 public:
-  virtual void read_samples(int n, int16_t *data);
+  virtual int read_samples(int n, int16_t *data);
 
 protected:
   void fetch_packet();
diff --git a/panda/src/movies/flacAudioCursor.cxx b/panda/src/movies/flacAudioCursor.cxx
index 0e3bbb163a..1c9d06984b 100644
--- a/panda/src/movies/flacAudioCursor.cxx
+++ b/panda/src/movies/flacAudioCursor.cxx
@@ -118,8 +118,10 @@ seek(double t) {
  * read.  Your buffer must be equal in size to N * channels.  Multiple-channel
  * audio will be interleaved.
  */
-void FlacAudioCursor::
+int FlacAudioCursor::
 read_samples(int n, int16_t *data) {
   int desired = n * _audio_channels;
-  _samples_read += drflac_read_s16(_drflac, desired, data) / _audio_channels;
+  n = drflac_read_s16(_drflac, desired, data) / _audio_channels;
+  _samples_read += n;
+  return n;
 }
diff --git a/panda/src/movies/flacAudioCursor.h b/panda/src/movies/flacAudioCursor.h
index 995be42e1e..93a48e5f32 100644
--- a/panda/src/movies/flacAudioCursor.h
+++ b/panda/src/movies/flacAudioCursor.h
@@ -37,7 +37,7 @@ PUBLISHED:
   virtual void seek(double offset);
 
 public:
-  virtual void read_samples(int n, int16_t *data);
+  virtual int read_samples(int n, int16_t *data);
 
   bool _is_valid;
 
diff --git a/panda/src/movies/microphoneAudioDS.cxx b/panda/src/movies/microphoneAudioDS.cxx
index 1ce78b0209..c04da23c3e 100644
--- a/panda/src/movies/microphoneAudioDS.cxx
+++ b/panda/src/movies/microphoneAudioDS.cxx
@@ -91,7 +91,7 @@ public:
   int _samples_per_buffer;
 
 public:
-  virtual void read_samples(int n, int16_t *data);
+  virtual int read_samples(int n, int16_t *data);
   virtual int ready() const;
 
 public:
@@ -323,7 +323,7 @@ MicrophoneAudioCursorDS::
 /**
  *
  */
-void MicrophoneAudioCursorDS::
+int MicrophoneAudioCursorDS::
 read_samples(int n, int16_t *data) {
   int orign = n;
   if (_handle) {
@@ -373,6 +373,7 @@ read_samples(int n, int16_t *data) {
   if (n > 0) {
     memcpy(data, 0, n*2*_audio_channels);
   }
+  return orign - n;
 }
 
 /**
diff --git a/panda/src/movies/movieAudioCursor.cxx b/panda/src/movies/movieAudioCursor.cxx
index 33acc0e10c..a725b56ad1 100644
--- a/panda/src/movies/movieAudioCursor.cxx
+++ b/panda/src/movies/movieAudioCursor.cxx
@@ -45,14 +45,14 @@ MovieAudioCursor::
  * read.  Your buffer must be equal in size to N * channels.  Multiple-channel
  * audio will be interleaved.
  */
-void MovieAudioCursor::
+int MovieAudioCursor::
 read_samples(int n, int16_t *data) {
 
   // This is the null implementation, which generates pure silence.  Normally,
   // this method will be overridden by a subclass.
 
   if (n <= 0) {
-    return;
+    return 0;
   }
 
   int desired = n * _audio_channels;
@@ -60,6 +60,7 @@ read_samples(int n, int16_t *data) {
     data[i] = 0;
   }
   _samples_read += n;
+  return n;
 }
 
 /**
diff --git a/panda/src/movies/movieAudioCursor.h b/panda/src/movies/movieAudioCursor.h
index b2d5d9bebe..28674f1215 100644
--- a/panda/src/movies/movieAudioCursor.h
+++ b/panda/src/movies/movieAudioCursor.h
@@ -51,7 +51,7 @@ PUBLISHED:
   std::string read_samples(int n);
 
 public:
-  virtual void read_samples(int n, int16_t *data);
+  virtual int read_samples(int n, int16_t *data);
 
 protected:
   PT(MovieAudio) _source;
diff --git a/panda/src/movies/opusAudioCursor.cxx b/panda/src/movies/opusAudioCursor.cxx
index 788a882885..814dc8fe04 100644
--- a/panda/src/movies/opusAudioCursor.cxx
+++ b/panda/src/movies/opusAudioCursor.cxx
@@ -228,7 +228,7 @@ seek(double t) {
  * read.  Your buffer must be equal in size to N * channels.  Multiple-channel
  * audio will be interleaved.
  */
-void OpusAudioCursor::
+int OpusAudioCursor::
 read_samples(int n, int16_t *data) {
   int16_t *end = data + (n * _audio_channels);
 
@@ -262,7 +262,9 @@ read_samples(int n, int16_t *data) {
   // Fill the rest of the buffer with silence.
   if (data < end) {
     memset(data, 0, (unsigned char *)end - (unsigned char *)data);
+    n -= (end - data) / _audio_channels;
   }
+  return n;
 }
 
 #endif // HAVE_OPUS
diff --git a/panda/src/movies/opusAudioCursor.h b/panda/src/movies/opusAudioCursor.h
index 11e05e4030..3e2137de5e 100644
--- a/panda/src/movies/opusAudioCursor.h
+++ b/panda/src/movies/opusAudioCursor.h
@@ -39,7 +39,7 @@ PUBLISHED:
   virtual void seek(double offset);
 
 public:
-  virtual void read_samples(int n, int16_t *data);
+  virtual int read_samples(int n, int16_t *data);
 
   bool _is_valid;
 
diff --git a/panda/src/movies/userDataAudio.cxx b/panda/src/movies/userDataAudio.cxx
index 4022b6b7f3..9490432dc0 100644
--- a/panda/src/movies/userDataAudio.cxx
+++ b/panda/src/movies/userDataAudio.cxx
@@ -57,12 +57,14 @@ open() {
  * read.  Your buffer must be equal in size to N * channels.  Multiple-channel
  * audio will be interleaved.
  */
-void UserDataAudio::
+int UserDataAudio::
 read_samples(int n, int16_t *data) {
   int ready = (_data.size() / _desired_channels);
   int desired = n * _desired_channels;
-  int avail = ready * _desired_channels;
-  if (avail > desired) avail = desired;
+  if (n > ready) {
+    n = ready;
+  }
+  int avail = n * _desired_channels;
   for (int i=0; i<avail; i++) {
     data[i] = _data[i];
   }
@@ -72,6 +74,7 @@ read_samples(int n, int16_t *data) {
   for (int i=0; i<avail; i++) {
     _data.pop_front();
   }
+  return n;
 }
 
 /**
diff --git a/panda/src/movies/userDataAudio.h b/panda/src/movies/userDataAudio.h
index 3901031fcb..b0b6e3bfbc 100644
--- a/panda/src/movies/userDataAudio.h
+++ b/panda/src/movies/userDataAudio.h
@@ -41,7 +41,7 @@ class EXPCL_PANDA_MOVIES UserDataAudio : public MovieAudio {
   void done(); // A promise not to write any more samples.
 
  private:
-  void read_samples(int n, int16_t *data);
+  int read_samples(int n, int16_t *data);
   void update_cursor();
   int _desired_rate;
   int _desired_channels;
diff --git a/panda/src/movies/userDataAudioCursor.cxx b/panda/src/movies/userDataAudioCursor.cxx
index 93bab206fa..5bf6b9538f 100644
--- a/panda/src/movies/userDataAudioCursor.cxx
+++ b/panda/src/movies/userDataAudioCursor.cxx
@@ -47,12 +47,12 @@ UserDataAudioCursor::
  * read.  Your buffer must be equal in size to N * channels.  Multiple-channel
  * audio will be interleaved.
  */
-void UserDataAudioCursor::
+int UserDataAudioCursor::
 read_samples(int n, int16_t *data) {
   UserDataAudio *source = (UserDataAudio*)(MovieAudio*)_source;
 
-  if(source->_remove_after_read) {
-    source->read_samples(n, data);
+  if (source->_remove_after_read) {
+    n = source->read_samples(n, data);
   }
   else {
     int offset = _samples_read * _audio_channels;
@@ -66,9 +66,12 @@ read_samples(int n, int16_t *data) {
     for (int i=avail; i<desired; i++) {
       data[i] = 0;
     }
+
+    n = avail / _audio_channels;
   }
 
   _samples_read += n;
+  return n;
 }
 
 /**
diff --git a/panda/src/movies/userDataAudioCursor.h b/panda/src/movies/userDataAudioCursor.h
index 5e0d75b85f..6e908c766a 100644
--- a/panda/src/movies/userDataAudioCursor.h
+++ b/panda/src/movies/userDataAudioCursor.h
@@ -33,7 +33,7 @@ PUBLISHED:
   virtual ~UserDataAudioCursor();
 
 public:
-  virtual void read_samples(int n, int16_t *data);
+  virtual int read_samples(int n, int16_t *data);
   virtual int ready() const;
   virtual void seek(double offset);
 
diff --git a/panda/src/movies/vorbisAudioCursor.cxx b/panda/src/movies/vorbisAudioCursor.cxx
index 80c5613b0c..f049d925d0 100644
--- a/panda/src/movies/vorbisAudioCursor.cxx
+++ b/panda/src/movies/vorbisAudioCursor.cxx
@@ -141,7 +141,7 @@ seek(double t) {
  * read.  Your buffer must be equal in size to N * channels.  Multiple-channel
  * audio will be interleaved.
  */
-void VorbisAudioCursor::
+int VorbisAudioCursor::
 read_samples(int n, int16_t *data) {
   int desired = n * _audio_channels;
 
@@ -186,6 +186,7 @@ read_samples(int n, int16_t *data) {
   }
 
   _samples_read += n;
+  return n;
 }
 
 /**
diff --git a/panda/src/movies/vorbisAudioCursor.h b/panda/src/movies/vorbisAudioCursor.h
index c82eec8184..cd74acc750 100644
--- a/panda/src/movies/vorbisAudioCursor.h
+++ b/panda/src/movies/vorbisAudioCursor.h
@@ -35,7 +35,7 @@ PUBLISHED:
   virtual void seek(double offset);
 
 public:
-  virtual void read_samples(int n, int16_t *data);
+  virtual int read_samples(int n, int16_t *data);
 
   bool _is_valid;
 
diff --git a/panda/src/movies/wavAudioCursor.cxx b/panda/src/movies/wavAudioCursor.cxx
index 4b58794d46..7c9f124598 100644
--- a/panda/src/movies/wavAudioCursor.cxx
+++ b/panda/src/movies/wavAudioCursor.cxx
@@ -358,13 +358,13 @@ seek(double t) {
  * read.  Your buffer must be equal in size to N * channels.  Multiple-channel
  * audio will be interleaved.
  */
-void WavAudioCursor::
+int WavAudioCursor::
 read_samples(int n, int16_t *data) {
   int desired = n * _audio_channels;
   int read_samples = std::min(desired, ((int) (_data_size - _data_pos)) / _bytes_per_sample);
 
   if (read_samples <= 0) {
-    return;
+    return 0;
   }
 
   switch (_format) {
@@ -455,8 +455,10 @@ read_samples(int n, int16_t *data) {
   // Fill the rest of the buffer with silence.
   if (read_samples < desired) {
     memset(data + read_samples, 0, (desired - read_samples) * 2);
+    n = read_samples / _audio_channels;
   }
 
   _data_pos = _stream->tellg() - _data_start;
-  _samples_read += read_samples / _audio_channels;
+  _samples_read += n;
+  return n;
 }
diff --git a/panda/src/movies/wavAudioCursor.h b/panda/src/movies/wavAudioCursor.h
index 21133b1c62..9ae03a5d7d 100644
--- a/panda/src/movies/wavAudioCursor.h
+++ b/panda/src/movies/wavAudioCursor.h
@@ -31,7 +31,7 @@ PUBLISHED:
   virtual void seek(double offset);
 
 public:
-  virtual void read_samples(int n, int16_t *data);
+  virtual int read_samples(int n, int16_t *data);
 
   bool _is_valid;