av_log callback handling overhaul

Move av_log callback handling from vd_ffmpeg.c to a new file
av_log.c and install the callback immediately when starting the
program. Main functionality improvements of the new code:

 - The old version only installed the callback when opening an FFmpeg
   video decoder. If nothing had triggered that then av_log() messages
   from other sources (libavformat, audio decoding, swscale usage)
   bypassed MPlayer's output system completely. Now the callback is
   always installed.

 - Current av_log message severity levels are handled correctly. The
   old code used MSGL_ERR for some messages that should be MSGL_V.

 - Message type is now set for libavformat contexts
   (MSGT_DEMUXER / MSGT_MUXER).

 - The old code did "mp_msg_test(type, mp_level)" before actually
   determining the type, so that it always used MSGT_FIXME. This led
   to some messages being incorrectly dropped in case the user
   had specified module-specific verbosity levels. The old check in
   question was originally motivated by performance problems when
   there were a lot of callbacks; however it's not clear whether the
   part about it skipping the type determination was intentional (most
   of the performance problems must have come from the way the
   original code used snprintf) and in my tests current FFmpeg
   libraries have not generated unreasonable amounts of callbacks
   anyway.

1 files changed, 111 insertions, 0 deletions

diff --git a/av_log.c b/av_log.c
new file mode 100644
index 0000000000..99f6e91a81
--- /dev/null
+++ b/av_log.c
@@ -0,0 +1,111 @@
+/*
+ * av_log to mp_msg converter
+ * Copyright (C) 2006 Michael Niedermayer
+ * Copyright (C) 2009 Uoti Urpala
+ *
+ * This file is part of MPlayer.
+ *
+ * MPlayer 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.
+ *
+ * MPlayer 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 MPlayer; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <stdlib.h>
+#include <stdbool.h>
+
+#include "config.h"
+#include "mp_msg.h"
+#include <libavutil/log.h>
+
+#ifdef CONFIG_LIBAVCODEC
+#include <libavcodec/avcodec.h>
+#endif
+
+#ifdef CONFIG_LIBAVFORMAT
+#include <libavformat/avformat.h>
+#endif
+
+static int av_log_level_to_mp_level(int av_level)
+{
+    if (av_level > AV_LOG_INFO)
+        return MSGL_V;
+    if (av_level > AV_LOG_WARNING)
+        return MSGL_INFO;
+    if (av_level > AV_LOG_ERROR)
+        return MSGL_WARN;
+    if (av_level > AV_LOG_FATAL)
+        return MSGL_ERR;
+    return MSGL_FATAL;
+}
+
+static int extract_msg_type_from_ctx(void *ptr)
+{
+    if (!ptr)
+        return MSGT_FIXME;
+
+    AVClass *avc = *(AVClass **)ptr;
+
+#ifdef CONFIG_LIBAVCODEC
+    if (!strcmp(avc->class_name, "AVCodecContext")) {
+        AVCodecContext *s = ptr;
+        if (s->codec) {
+            if (s->codec->type == CODEC_TYPE_AUDIO) {
+                if (s->codec->decode)
+                    return MSGT_DECAUDIO;
+            } else if (s->codec->type == CODEC_TYPE_VIDEO) {
+                if (s->codec->decode)
+                    return MSGT_DECVIDEO;
+            }
+            // FIXME subtitles, encoders
+            // What msgt for them? There is nothing appropriate...
+        }
+        return MSGT_FIXME;
+    }
+#endif
+
+#ifdef CONFIG_LIBAVFORMAT
+    if (!strcmp(avc->class_name, "AVFormatContext")) {
+        AVFormatContext *s = ptr;
+        if (s->iformat)
+            return MSGT_DEMUXER;
+        else if (s->oformat)
+            return MSGT_MUXER;
+        return MSGT_FIXME;
+    }
+#endif
+
+    return MSGT_FIXME;
+}
+
+static void mp_msg_av_log_callback(void *ptr, int level, const char *fmt,
+                                   va_list vl)
+{
+    static bool print_prefix = 1;
+    AVClass *avc = ptr ? *(AVClass **)ptr : NULL;
+    int mp_level = av_log_level_to_mp_level(level);
+    int type = extract_msg_type_from_ctx(ptr);
+
+    if (!mp_msg_test(type, mp_level))
+        return;
+
+    if (print_prefix && avc)
+        mp_msg(type, mp_level, "[%s @ %p]", avc->item_name(ptr), avc);
+    print_prefix = fmt[strlen(fmt) - 1] == '\n';
+
+    mp_msg_va(type, mp_level, fmt, vl);
+}
+
+void set_av_log_callback(void)
+{
+  av_log_set_callback(mp_msg_av_log_callback);
+}