decoder/ffmpeg: move code to class FfmpegBuffer

Makefile.am

@@ -817,6 +817,7 @@ endif
 if ENABLE_FFMPEG
 noinst_LIBRARIES += libffmpeg.a
 libffmpeg_a_SOURCES = \
+	src/lib/ffmpeg/Buffer.hxx \
 	src/lib/ffmpeg/LogError.cxx src/lib/ffmpeg/LogError.hxx \
 	src/lib/ffmpeg/Error.cxx src/lib/ffmpeg/Error.hxx \
 	src/lib/ffmpeg/Domain.cxx src/lib/ffmpeg/Domain.hxx

src/decoder/plugins/FfmpegDecoderPlugin.cxx

@@ -24,6 +24,7 @@
 #include "FfmpegDecoderPlugin.hxx"
 #include "lib/ffmpeg/Domain.hxx"
 #include "lib/ffmpeg/LogError.hxx"
+#include "lib/ffmpeg/Buffer.hxx"
 #include "../DecoderAPI.hxx"
 #include "FfmpegMetaData.hxx"
 #include "tag/TagBuilder.hxx"
@@ -275,7 +276,7 @@ static int
 copy_interleave_frame(const AVCodecContext *codec_context,
 		      const AVFrame *frame,
 		      uint8_t **output_buffer,
-		      uint8_t **global_buffer, int *global_buffer_size)
+		      FfmpegBuffer &global_buffer)
 {
 	int plane_size;
 	const int data_size =
@@ -288,17 +289,11 @@ copy_interleave_frame(const AVCodecContext *codec_context,
 
 	if (av_sample_fmt_is_planar(codec_context->sample_fmt) &&
 	    codec_context->channels > 1) {
-		if(*global_buffer_size < data_size) {
-			av_freep(global_buffer);
+		*output_buffer = global_buffer.GetT<uint8_t>(data_size);
+		if (*output_buffer == nullptr)
+			/* Not enough memory - shouldn't happen */
+			return AVERROR(ENOMEM);
 
-			*global_buffer = (uint8_t*)av_malloc(data_size);
-
-			if (!*global_buffer)
-				/* Not enough memory - shouldn't happen */
-				return AVERROR(ENOMEM);
-			*global_buffer_size = data_size;
-		}
-		*output_buffer = *global_buffer;
 		copy_interleave_frame2(*output_buffer, frame->extended_data,
 				       frame->nb_samples,
 				       codec_context->channels,
@@ -316,7 +311,7 @@ ffmpeg_send_packet(Decoder &decoder, InputStream &is,
 		   AVCodecContext *codec_context,
 		   const AVStream *stream,
 		   AVFrame *frame,
-		   uint8_t **buffer, int *buffer_size)
+		   FfmpegBuffer &buffer)
 {
 	if (packet->pts >= 0 && packet->pts != (int64_t)AV_NOPTS_VALUE) {
 		auto start = start_time_fallback(*stream);
@@ -346,7 +341,7 @@ ffmpeg_send_packet(Decoder &decoder, InputStream &is,
 			audio_size = copy_interleave_frame(codec_context,
 							   frame,
 							   &output_buffer,
-							   buffer, buffer_size);
+							   buffer);
 			if (audio_size < 0) {
 				/* this must be a serious error,
 				   e.g. OOM */
@@ -667,8 +662,7 @@ ffmpeg_decode(Decoder &decoder, InputStream &input)
 		return;
 	}
 
-	uint8_t *interleaved_buffer = nullptr;
-	int interleaved_buffer_size = 0;
+	FfmpegBuffer interleaved_buffer;
 
 	DecoderCommand cmd;
 	do {
@@ -686,7 +680,7 @@ ffmpeg_decode(Decoder &decoder, InputStream &input)
 						 &packet, codec_context,
 						 av_stream,
 						 frame,
-						 &interleaved_buffer, &interleaved_buffer_size);
+						 interleaved_buffer);
 		else
 			cmd = decoder_get_command(decoder);
 
@@ -715,7 +709,6 @@ ffmpeg_decode(Decoder &decoder, InputStream &input)
 #else
 	av_freep(&frame);
 #endif
-	av_freep(&interleaved_buffer);
 
 	avcodec_close(codec_context);
 	avformat_close_input(&format_context);

src/lib/ffmpeg/Buffer.hxx

@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_FFMPEG_BUFFER_HXX
+#define MPD_FFMPEG_BUFFER_HXX
+
+extern "C" {
+#include <libavutil/avutil.h>
+
+#if LIBAVUTIL_VERSION_INT >= AV_VERSION_INT(52, 18, 0)
+#define HAVE_AV_FAST_MALLOC
+#include <libavutil/mem.h>
+#else
+#include <libavcodec/avcodec.h>
+#if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(52, 25, 0)
+#define HAVE_AV_FAST_MALLOC
+#endif
+#endif
+}
+
+#include <stddef.h>
+
+/* suppress the ffmpeg compatibility macro */
+#ifdef SampleFormat
+#undef SampleFormat
+#endif
+
+class FfmpegBuffer {
+	void *data;
+	unsigned size;
+
+public:
+	FfmpegBuffer():data(nullptr), size(0) {}
+
+	~FfmpegBuffer() {
+		av_free(data);
+	}
+
+	void *Get(size_t min_size) {
+#ifdef HAVE_AV_FAST_MALLOC
+		av_fast_malloc(&data, &size, min_size);
+#else
+		void *new_data = av_fast_realloc(data, &size, min_size);
+		if (new_data == nullptr)
+			return AVERROR(ENOMEM);
+		data = new_data;
+#endif
+		return data;
+	}
+
+	template<typename T>
+	T *GetT(size_t n) {
+		return (T *)Get(n * sizeof(T));
+	}
+};
+
+#endif