1 files changed, 405 insertions, 0 deletions
diff --git a/src/Classes/UMediaCore_FFmpeg.pas b/src/Classes/UMediaCore_FFmpeg.pas
new file mode 100644
index 00000000..cdd320ac
--- /dev/null
+++ b/src/Classes/UMediaCore_FFmpeg.pas
@@ -0,0 +1,405 @@
+unit UMediaCore_FFmpeg;
+
+interface
+
+{$IFDEF FPC}
+  {$MODE Delphi}
+{$ENDIF}
+
+{$I switches.inc}
+
+uses
+  UMusic,
+  avcodec,
+  avformat,
+  avutil,
+  ULog,
+  sdl;
+
+type
+  PPacketQueue = ^TPacketQueue;
+  TPacketQueue = class
+    private
+      FirstListEntry: PAVPacketList;
+      LastListEntry:  PAVPacketList;
+      PacketCount: integer;
+      Mutex:     PSDL_Mutex;
+      Condition: PSDL_Cond;
+      Size: integer;
+      AbortRequest: boolean;
+    public
+      constructor Create();
+      destructor Destroy(); override;
+
+      function Put(Packet : PAVPacket): integer;
+      function PutStatus(StatusFlag: integer; StatusInfo: Pointer): integer;
+      procedure FreeStatusInfo(var Packet: TAVPacket);
+      function GetStatusInfo(var Packet: TAVPacket): Pointer;
+      function Get(var Packet: TAVPacket; Blocking: boolean): integer;
+      function GetSize(): integer;
+      procedure Flush();
+      procedure Abort();
+      function IsAborted(): boolean;
+  end;
+
+const
+  STATUS_PACKET: PChar = 'STATUS_PACKET';
+const
+  PKT_STATUS_FLAG_EOF     = 1; // signal end-of-file
+  PKT_STATUS_FLAG_FLUSH   = 2; // request the decoder to flush its avcodec decode buffers
+  PKT_STATUS_FLAG_ERROR   = 3; // signal an error state
+  PKT_STATUS_FLAG_EMPTY   = 4; // request the decoder to output empty data (silence or black frames)
+
+type
+  TMediaCore_FFmpeg = class
+    private
+      AVCodecLock: PSDL_Mutex;
+    public
+      constructor Create();
+      destructor Destroy(); override;
+      class function GetInstance(): TMediaCore_FFmpeg;
+
+      function GetErrorString(ErrorNum: integer): string;
+      function FindStreamIDs(FormatCtx: PAVFormatContext; out FirstVideoStream, FirstAudioStream: integer ): boolean;
+      function FindAudioStreamIndex(FormatCtx: PAVFormatContext): integer;
+      function ConvertFFmpegToAudioFormat(FFmpegFormat: TSampleFormat; out Format: TAudioSampleFormat): boolean;
+      procedure LockAVCodec();
+      procedure UnlockAVCodec();
+  end;
+
+implementation
+
+uses
+  SysUtils;
+
+var
+  Instance: TMediaCore_FFmpeg;
+
+constructor TMediaCore_FFmpeg.Create();
+begin
+  inherited;
+  AVCodecLock := SDL_CreateMutex();
+end;
+
+destructor TMediaCore_FFmpeg.Destroy();
+begin
+  SDL_DestroyMutex(AVCodecLock);
+  inherited;
+end;
+
+class function TMediaCore_FFmpeg.GetInstance(): TMediaCore_FFmpeg;
+begin
+  if (not Assigned(Instance)) then
+    Instance := TMediaCore_FFmpeg.Create();
+  Result := Instance;
+end;
+
+procedure TMediaCore_FFmpeg.LockAVCodec();
+begin
+  SDL_mutexP(AVCodecLock);
+end;
+
+procedure TMediaCore_FFmpeg.UnlockAVCodec();
+begin
+  SDL_mutexV(AVCodecLock);
+end;
+
+function TMediaCore_FFmpeg.GetErrorString(ErrorNum: integer): string;
+begin
+  case ErrorNum of
+    AVERROR_IO:           Result := 'AVERROR_IO';
+    AVERROR_NUMEXPECTED:  Result := 'AVERROR_NUMEXPECTED';
+    AVERROR_INVALIDDATA:  Result := 'AVERROR_INVALIDDATA';
+    AVERROR_NOMEM:        Result := 'AVERROR_NOMEM';
+    AVERROR_NOFMT:        Result := 'AVERROR_NOFMT';
+    AVERROR_NOTSUPP:      Result := 'AVERROR_NOTSUPP';
+    AVERROR_NOENT:        Result := 'AVERROR_NOENT';
+    AVERROR_PATCHWELCOME: Result := 'AVERROR_PATCHWELCOME';
+    else                  Result := 'AVERROR_#'+inttostr(ErrorNum);
+  end;
+end;
+
+{
+  @param(FormatCtx is a PAVFormatContext returned from av_open_input_file )
+  @param(FirstVideoStream is an OUT value of type integer, this is the index of the video stream)
+  @param(FirstAudioStream is an OUT value of type integer, this is the index of the audio stream)
+  @returns(@true on success, @false otherwise)
+}
+function TMediaCore_FFmpeg.FindStreamIDs(FormatCtx: PAVFormatContext; out FirstVideoStream, FirstAudioStream: integer): boolean;
+var
+  i: integer;
+  Stream: PAVStream;
+begin
+  // find the first video stream
+  FirstAudioStream := -1;
+  FirstVideoStream := -1;
+
+  for i := 0 to FormatCtx.nb_streams-1 do
+  begin
+    Stream := FormatCtx.streams[i];
+
+    if (Stream.codec.codec_type = CODEC_TYPE_VIDEO) and
+       (FirstVideoStream < 0) then
+    begin
+      FirstVideoStream := i;
+    end;
+
+    if (Stream.codec.codec_type = CODEC_TYPE_AUDIO) and
+       (FirstAudioStream < 0) then
+    begin
+      FirstAudioStream := i;
+    end;
+  end;
+
+  // return true if either an audio- or video-stream was found
+  Result := (FirstAudioStream > -1) or
+            (FirstVideoStream > -1) ;
+end;
+
+function TMediaCore_FFmpeg.FindAudioStreamIndex(FormatCtx: PAVFormatContext): integer;
+var
+  i: integer;
+  StreamIndex: integer;
+  Stream: PAVStream;
+begin
+  // find the first audio stream
+  StreamIndex := -1;
+
+  for i := 0 to FormatCtx^.nb_streams-1 do
+  begin
+    Stream := FormatCtx^.streams[i];
+
+    if (Stream.codec^.codec_type = CODEC_TYPE_AUDIO) then
+    begin
+      StreamIndex := i;
+      Break;
+    end;
+  end;
+
+  Result := StreamIndex;
+end;
+
+function TMediaCore_FFmpeg.ConvertFFmpegToAudioFormat(FFmpegFormat: TSampleFormat; out Format: TAudioSampleFormat): boolean;
+begin
+  case FFmpegFormat of
+    SAMPLE_FMT_U8:  Format := asfU8;
+    SAMPLE_FMT_S16: Format := asfS16;
+    SAMPLE_FMT_S24: Format := asfS24;
+    SAMPLE_FMT_S32: Format := asfS32;
+    SAMPLE_FMT_FLT: Format := asfFloat;
+    else begin
+      Result := false;
+      Exit;
+    end;
+  end;
+  Result := true;
+end;
+
+{ TPacketQueue }
+
+constructor TPacketQueue.Create();
+begin
+  inherited;
+
+  FirstListEntry := nil;
+  LastListEntry  := nil;
+  PacketCount := 0;
+  Size := 0;
+
+  Mutex := SDL_CreateMutex();
+  Condition := SDL_CreateCond();
+end;
+
+destructor TPacketQueue.Destroy();
+begin
+  Flush();
+  SDL_DestroyMutex(Mutex);
+  SDL_DestroyCond(Condition);
+  inherited;
+end;
+
+procedure TPacketQueue.Abort();
+begin
+  SDL_LockMutex(Mutex);
+
+  AbortRequest := true;
+
+  SDL_CondBroadcast(Condition);
+  SDL_UnlockMutex(Mutex);
+end;
+
+function TPacketQueue.IsAborted(): boolean;
+begin
+  SDL_LockMutex(Mutex);
+  Result := AbortRequest;
+  SDL_UnlockMutex(Mutex);
+end;
+
+function TPacketQueue.Put(Packet : PAVPacket): integer;
+var
+  CurrentListEntry : PAVPacketList;
+begin
+  Result := -1;
+
+  if (Packet = nil) then
+    Exit;
+
+  if (PChar(Packet^.data) <> STATUS_PACKET) then
+  begin
+    if (av_dup_packet(Packet) < 0) then
+      Exit;
+  end;
+
+  CurrentListEntry := av_malloc(SizeOf(TAVPacketList));
+  if (CurrentListEntry = nil) then
+    Exit;
+
+  CurrentListEntry^.pkt  := Packet^;
+  CurrentListEntry^.next := nil;
+
+  SDL_LockMutex(Mutex);
+  try
+    if (LastListEntry = nil) then
+      FirstListEntry := CurrentListEntry
+    else
+      LastListEntry^.next := CurrentListEntry;
+
+    LastListEntry := CurrentListEntry;
+    Inc(PacketCount);
+
+    Size := Size + CurrentListEntry^.pkt.size;
+    SDL_CondSignal(Condition);
+  finally
+    SDL_UnlockMutex(Mutex);
+  end;
+
+  Result := 0;
+end;
+
+(**
+ * Adds a status packet (EOF, Flush, etc.) to the end of the queue.
+ * StatusInfo can be used to pass additional information to the decoder.
+ * Only assign nil or a valid pointer to data allocated with Getmem() to
+ * StatusInfo because the pointer will be disposed with Freemem() on a call
+ * to Flush(). If the packet is removed from the queue it is the decoder's
+ * responsibility to free the StatusInfo data with FreeStatusInfo().
+ *)
+function TPacketQueue.PutStatus(StatusFlag: integer; StatusInfo: Pointer): integer;
+var
+  TempPacket: PAVPacket;
+begin
+  // create temp. package
+  TempPacket := av_malloc(SizeOf(TAVPacket));
+  if (TempPacket = nil) then
+  begin
+    Result := -1;
+    Exit;
+  end;
+  // init package
+  av_init_packet(TempPacket^);
+  TempPacket^.data  := Pointer(STATUS_PACKET);
+  TempPacket^.flags := StatusFlag;
+  TempPacket^.priv  := StatusInfo;
+  // put a copy of the package into the queue
+  Result := Put(TempPacket);
+  // data has been copied -> delete temp. package
+  av_free(TempPacket);
+end;
+
+procedure TPacketQueue.FreeStatusInfo(var Packet: TAVPacket);
+begin
+  if (Packet.priv <> nil) then
+    FreeMem(Packet.priv);
+end;
+
+function TPacketQueue.GetStatusInfo(var Packet: TAVPacket): Pointer;
+begin
+  Result := Packet.priv;
+end;
+
+function TPacketQueue.Get(var Packet: TAVPacket; Blocking: boolean): integer;
+var
+  CurrentListEntry: PAVPacketList;
+const
+  WAIT_TIMEOUT = 10; // timeout in ms
+begin
+  Result := -1;
+
+  SDL_LockMutex(Mutex);
+  try
+    while (true) do
+    begin
+      if (AbortRequest) then
+        Exit;
+
+      CurrentListEntry := FirstListEntry;
+      if (CurrentListEntry <> nil) then
+      begin
+        FirstListEntry := CurrentListEntry^.next;
+        if (FirstListEntry = nil) then
+          LastListEntry := nil;
+        Dec(PacketCount);
+
+        Size := Size - CurrentListEntry^.pkt.size;
+        Packet := CurrentListEntry^.pkt;
+        av_free(CurrentListEntry);
+
+        Result := 1;
+        Break;
+      end
+      else if (not Blocking) then
+      begin
+        Result := 0;
+        Break;
+      end
+      else
+      begin
+        // block until a new package arrives,
+        // but do not wait till infinity to avoid deadlocks
+        if (SDL_CondWaitTimeout(Condition, Mutex, WAIT_TIMEOUT) = SDL_MUTEX_TIMEDOUT) then
+        begin
+          Result := 0;
+          Break;
+        end;
+      end;
+    end;
+  finally
+    SDL_UnlockMutex(Mutex);
+  end;
+end;
+
+function TPacketQueue.GetSize(): integer;
+begin
+  SDL_LockMutex(Mutex);
+  Result := Size;
+  SDL_UnlockMutex(Mutex);
+end;
+
+procedure TPacketQueue.Flush();
+var
+  CurrentListEntry, TempListEntry: PAVPacketList;
+begin
+  SDL_LockMutex(Mutex);
+
+  CurrentListEntry := FirstListEntry;
+  while(CurrentListEntry <> nil) do
+  begin
+    TempListEntry := CurrentListEntry^.next;
+    // free status data
+    if (PChar(CurrentListEntry^.pkt.data) = STATUS_PACKET) then
+      FreeStatusInfo(CurrentListEntry^.pkt);
+    // free packet data
+    av_free_packet(@CurrentListEntry^.pkt);
+    // Note: param must be a pointer to a pointer!
+    av_freep(@CurrentListEntry);
+    CurrentListEntry := TempListEntry;
+  end;
+  LastListEntry := nil;
+  FirstListEntry := nil;
+  PacketCount := 0;
+  Size := 0;
+
+  SDL_UnlockMutex(Mutex);
+end;
+
+end.