decoder/ffmpeg: log detailed error message

Makefile.am

@@ -799,6 +799,7 @@ endif
 if HAVE_FFMPEG
 noinst_LIBRARIES += libffmpeg.a
 libffmpeg_a_SOURCES = \
+	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
 libffmpeg_a_CPPFLAGS = $(AM_CPPFLAGS) \

NEWS

@@ -1,4 +1,6 @@
 ver 0.19.18 (not yet released)
+* decoder
+  - ffmpeg: log detailed error message
 
 ver 0.19.17 (2016/07/09)
 * decoder

src/decoder/plugins/FfmpegDecoderPlugin.cxx

@@ -23,6 +23,7 @@
 #include "config.h"
 #include "FfmpegDecoderPlugin.hxx"
 #include "lib/ffmpeg/Domain.hxx"
+#include "lib/ffmpeg/LogError.hxx"
 #include "../DecoderAPI.hxx"
 #include "FfmpegMetaData.hxx"
 #include "tag/TagHandler.hxx"
@@ -379,8 +380,7 @@ ffmpeg_send_packet(Decoder &decoder, InputStream &is,
 						&packet);
 		if (len < 0) {
 			/* if error, we skip the frame */
-			LogDefault(ffmpeg_domain,
+			LogFfmpegError(len, "decoding failed, frame skipped");
-				   "decoding failed, frame skipped");
 			break;
 		}
 
@@ -394,6 +394,7 @@ ffmpeg_send_packet(Decoder &decoder, InputStream &is,
 			if (audio_size < 0) {
 				/* this must be a serious error,
 				   e.g. OOM */
+				LogFfmpegError(audio_size);
 				return DecoderCommand::STOP;
 			}
 		}

src/lib/ffmpeg/LogError.cxx

@@ -0,0 +1,45 @@
+/*
+ * 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.
+ */
+
+#include "config.h"
+#include "LogError.hxx"
+#include "Domain.hxx"
+#include "Log.hxx"
+
+#include <cstdint> /* needed due to libavutil bug */
+
+extern "C" {
+#include <libavutil/error.h>
+}
+
+void
+LogFfmpegError(int errnum)
+{
+	char msg[256];
+	av_strerror(errnum, msg, sizeof(msg));
+	LogError(ffmpeg_domain, msg);
+}
+
+void
+LogFfmpegError(int errnum, const char *prefix)
+{
+	char msg[256];
+	av_strerror(errnum, msg, sizeof(msg));
+	FormatError(ffmpeg_domain, "%s: %s", prefix, msg);
+}

src/lib/ffmpeg/LogError.hxx

@@ -0,0 +1,29 @@
+/*
+ * 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_LOG_ERROR_HXX
+#define MPD_FFMPEG_LOG_ERROR_HXX
+
+void
+LogFfmpegError(int errnum);
+
+void
+LogFfmpegError(int errnum, const char *prefix);
+
+#endif