Fix #5: No more overreading

include/metadata.h

@@ -10,6 +10,7 @@ struct TrackMetadata {
   ~TrackMetadata();
 
   int64_t Length; // milliseconds
+  int64_t  LengthSamples;
   int64_t Fadeout;
   std::string Title;
   std::string Artist;

include/plugin.h

@@ -26,6 +26,7 @@ struct PluginState {
   ~PluginState();
 
   DB_fileinfo_t fFileInfo;
+  int readsample;
   bool fInit;
   uint32_t hints;
   TrackMetadata fMetadata;

src/metadata.cpp

@@ -3,7 +3,7 @@
 #include "psflib.h"
 
 TrackMetadata::TrackMetadata()
-  : Length(0), Fadeout(0), Title(""), Artist(""), Year(""), Game(""), Comment(""), set_RG_album(false), RG_AGAIN(0), RG_APEAK(1), set_RG_track(false), RG_TGAIN(0), RG_TPEAK(1) {
+  : Length(0), LengthSamples(0), Fadeout(0), Title(""), Artist(""), Year(""), Game(""), Comment(""), set_RG_album(false), RG_AGAIN(0), RG_APEAK(1), set_RG_track(false), RG_TGAIN(0), RG_TPEAK(1) {
   // explicitly clear the map to avoid any issues with reused memory
   OtherMeta.clear();
 }

src/play.cpp

@@ -131,13 +131,13 @@ int gsf_read(DB_fileinfo_t *_info, char *buffer, int nbytes) {
   }
 
 #ifdef BUILD_DEBUG
-  tracedbg("GSF DEBUG: readpos: %d, length: %d\n", _info->readpos, state->fMetadata.Length / 1000);
+  tracedbg("GSF DEBUG: readsample: %d, length: %d\n", state->readsample, state->fMetadata.LengthSamples);
   #ifdef STDERR_DEBUGGING
-  std::cerr << "GSF DEBUG: readpos: " << _info->readpos << ", length: " << state->fMetadata.Length / 1000 << std::endl;
+  std::cerr << "GSF DEBUG: readsample: " << state->readsample << ", length: " << state->fMetadata.LengthSamples << std::endl;
   #endif
   #endif
   if (!(deadbeef->streamer_get_repeat () == DDB_REPEAT_SINGLE) || !(state->hints & DDB_DECODER_HINT_CAN_LOOP)) {
-    if (_info->readpos >= (float)state->fMetadata.Length / 1000) {
+    if (state->readsample >= (float)state->fMetadata.LengthSamples) {
 #ifdef BUILD_DEBUG
       tracedbg("GSF DEBUG: end of track\n");
 #endif
@@ -177,6 +177,11 @@ int gsf_read(DB_fileinfo_t *_info, char *buffer, int nbytes) {
   std::cerr << "GSF DEBUG: Must copy " << to_copy << " bytes" << std::endl;
   #endif
   #endif
+  // if we would copy more samples than the length of the file, we
+  // need to trim the buffer
+  size_t remaining_samples = state->fMetadata.LengthSamples - state->readsample;
+  if (to_copy > remaining_samples)
+    to_copy = remaining_samples;
   unsigned char *head_sample = &state->output.sample_buffer[0];
   std::copy(head_sample, head_sample+to_copy, buffer);
 
@@ -194,6 +199,7 @@ int gsf_read(DB_fileinfo_t *_info, char *buffer, int nbytes) {
 
   // 16-bit samples, stereo, so 4 bytes per sample
   // 44100 samples per second
+  state->readsample += nbytes / 4;
   _info->readpos += (float)nbytes / 44100 / 4;
 
   return to_copy;
@@ -208,6 +214,7 @@ int gsf_seek(DB_fileinfo_t *info, float seconds) {
   if (info->readpos > seconds) {
     CPUReset(&state->fEmulator);
     info->readpos = 0;
+    state->readsample = 0;
   }
 
   float to_seek = seconds - info->readpos;
@@ -231,6 +238,7 @@ int gsf_seek(DB_fileinfo_t *info, float seconds) {
         #endif
         #endif
         // discard the entire buffer if there's less data than we need
+        state->readsample += in_buffer / 4;
         in_buffer = 0;
         to_seek -= seconds_in_buffer;
         continue;
@@ -246,6 +254,7 @@ int gsf_seek(DB_fileinfo_t *info, float seconds) {
       std::copy(head_sample + bytes_needed,
                 head_sample + in_buffer,
                 head_sample);
+      state->readsample += in_buffer / 4;
       in_buffer -= bytes_needed;
       to_seek = 0;
       break;

src/plugin.cpp

@@ -9,7 +9,7 @@
 // plugin state will often occupy the same memory as a previous state,
 // must be careful to ensure everything is properly initialised to
 // avoid segfaults
-PluginState::PluginState() : fFileInfo(), fInit(false), hints(0), fMetadata(), output(), ROM(), entry_point(0), set_entry(false), fEmulator() {}
+PluginState::PluginState() : fFileInfo(), readsample(0), fInit(false), hints(0), fMetadata(), output(), ROM(), entry_point(0), set_entry(false), fEmulator() {}
 
 PluginState::~PluginState() {
   if (fInit) {

src/psflib.cpp

@@ -161,6 +161,8 @@ int gsf_load_callback(void *context, const uint8_t *exe, size_t exe_size,
   return 0;
 }
 
+constexpr int sample_rate = 44100; // samples per second
+
 // metadata callback for psflib
 int gsf_info_callback(void *context, const char *name, const char *value) {
   TrackMetadata *meta = (TrackMetadata*)context;
@@ -169,9 +171,10 @@ int gsf_info_callback(void *context, const char *name, const char *value) {
     // ignore -- we don't want the _lib entries showing up, as they
     // are internal use only
     return 0;
-  else if (!strcasecmp(name, "length"))
-    meta->Length = parse_time(value);
-  else if (!strcasecmp(name, "fade"))
+  else if (!strcasecmp(name, "length")) {
+    meta->Length = parse_time(value); // milliseconds
+    meta->LengthSamples = 44100 * meta->Length / 1000;
+  } else if (!strcasecmp(name, "fade"))
     meta->Fadeout = parse_time(value);
   else if (!strcasecmp(name, "title"))
     meta->Title = value;