LibMedia: Allow signalling of EOF to decoders

This is used by FFmpeg's H.264 decoder to determine when to output any
buffered frames after data runs out.

Libraries/LibMedia/AudioDecoder.h

@@ -20,6 +20,7 @@ public:
     virtual ~AudioDecoder() { }
 
     virtual DecoderErrorOr<void> receive_coded_data(AK::Duration timestamp, ReadonlyBytes coded_data) = 0;
+    virtual void signal_end_of_stream() = 0;
     // Writes all buffered audio samples to the provided block.
     virtual DecoderErrorOr<void> write_next_block(AudioBlock&) = 0;
 

Libraries/LibMedia/FFmpeg/FFmpegAudioDecoder.cpp

@@ -104,6 +104,17 @@ DecoderErrorOr<void> FFmpegAudioDecoder::receive_coded_data(AK::Duration timesta
     }
 }
 
+void FFmpegAudioDecoder::signal_end_of_stream()
+{
+    m_packet->data = nullptr;
+    m_packet->size = 0;
+    m_packet->pts = 0;
+    m_packet->dts = 0;
+
+    auto result = avcodec_send_packet(m_codec_context, m_packet);
+    VERIFY(result == 0 || result == AVERROR_EOF);
+}
+
 template<typename T>
 static float float_sample_from_frame_data(u8** data, size_t plane, size_t index);
 

Libraries/LibMedia/FFmpeg/FFmpegAudioDecoder.h

@@ -20,6 +20,7 @@ public:
     virtual ~FFmpegAudioDecoder() override;
 
     virtual DecoderErrorOr<void> receive_coded_data(AK::Duration timestamp, ReadonlyBytes coded_data) override;
+    virtual void signal_end_of_stream() override;
     // Writes all buffered audio samples to the provided block.
     virtual DecoderErrorOr<void> write_next_block(AudioBlock&) override;
 

Libraries/LibMedia/FFmpeg/FFmpegVideoDecoder.cpp

@@ -130,6 +130,17 @@ DecoderErrorOr<void> FFmpegVideoDecoder::receive_coded_data(AK::Duration timesta
     }
 }
 
+void FFmpegVideoDecoder::signal_end_of_stream()
+{
+    m_packet->data = nullptr;
+    m_packet->size = 0;
+    m_packet->pts = 0;
+    m_packet->dts = 0;
+
+    auto result = avcodec_send_packet(m_codec_context, m_packet);
+    VERIFY(result == 0 || result == AVERROR_EOF);
+}
+
 DecoderErrorOr<NonnullOwnPtr<VideoFrame>> FFmpegVideoDecoder::get_decoded_frame()
 {
     auto result = avcodec_receive_frame(m_codec_context, m_frame);

Libraries/LibMedia/FFmpeg/FFmpegVideoDecoder.h

@@ -21,6 +21,7 @@ public:
     virtual ~FFmpegVideoDecoder() override;
 
     virtual DecoderErrorOr<void> receive_coded_data(AK::Duration timestamp, ReadonlyBytes coded_data) override;
+    virtual void signal_end_of_stream() override;
     virtual DecoderErrorOr<NonnullOwnPtr<VideoFrame>> get_decoded_frame() override;
 
     virtual void flush() override;

Libraries/LibMedia/VideoDecoder.h

@@ -20,6 +20,7 @@ public:
 
     virtual DecoderErrorOr<void> receive_coded_data(AK::Duration timestamp, ReadonlyBytes coded_data) = 0;
     DecoderErrorOr<void> receive_coded_data(AK::Duration timestamp, ByteBuffer const& coded_data) { return receive_coded_data(timestamp, coded_data.span()); }
+    virtual void signal_end_of_stream() = 0;
     virtual DecoderErrorOr<NonnullOwnPtr<VideoFrame>> get_decoded_frame() = 0;
 
     virtual void flush() = 0;