ffserver_config: handle codec private options

This commit allows to set codec's private option.
As side effect, it also improves preset support.
Signed-off-by: Lukasz Marek <lukasz.m.luki2@gmail.com>

Changelog

@@ -12,6 +12,7 @@ version <next>:
 - UDP-Lite support (RFC 3828)
 - xBR scaling filter
 - AVFoundation screen capturing support
+- ffserver supports codec private options
 
 version 2.4:
 - Icecast protocol

doc/ffserver.texi

@@ -589,8 +589,9 @@ Set sampling frequency for audio. When using low bitrates, you should
 lower this frequency to 22050 or 11025. The supported frequencies
 depend on the selected audio codec.
 
-@item AVOptionAudio @var{option} @var{value} (@emph{encoding,audio})
-Set generic option for audio stream.
+@item AVOptionAudio [@var{codec}:]@var{option} @var{value} (@emph{encoding,audio})
+Set generic or private option for audio stream.
+Private option must be prefixed with codec name or codec must be defined before.
 
 @item AVPresetAudio @var{preset} (@emph{encoding,audio})
 Set preset for audio stream.
@@ -667,8 +668,9 @@ Set video @option{qdiff} encoding option.
 @item DarkMask @var{float} (@emph{encoding,video})
 Set @option{lumi_mask}/@option{dark_mask} encoding options.
 
-@item AVOptionVideo @var{option} @var{value} (@emph{encoding,video})
-Set generic option for video stream.
+@item AVOptionVideo [@var{codec}:]@var{option} @var{value} (@emph{encoding,video})
+Set generic or private option for video stream.
+Private option must be prefixed with codec name or codec must be defined before.
 
 @item AVPresetVideo @var{preset} (@emph{encoding,video})
 Set preset for video stream.

ffserver_config.h

@@ -107,15 +107,18 @@ typedef struct FFServerConfig {
     int errors;
     int warnings;
     // Following variables MUST NOT be used outside configuration parsing code.
-    enum AVCodecID audio_id;
-    enum AVCodecID video_id;
+    enum AVCodecID guessed_audio_codec_id;
+    enum AVCodecID guessed_video_codec_id;
     AVDictionary *video_opts;     /* AVOptions for video encoder */
     AVDictionary *video_conf;     /* Values stored in video AVCodecContext.fields */
     AVDictionary *audio_opts;     /* AVOptions for audio encoder */
     AVDictionary *audio_conf;     /* Values stored in audio AVCodecContext.fields */
     char *video_preset;
     char *audio_preset;
-    AVCodecContext *dummy_ctx;    /* Used internally to test AVOptions. Not to be used anywhere else */
+    AVCodecContext *dummy_actx;   /* Used internally to test audio AVOptions. */
+    AVCodecContext *dummy_vctx;   /* Used internally to test video AVOptions. */
+    int no_audio;
+    int no_video;
 } FFServerConfig;
 
 void ffserver_get_arg(char *buf, int buf_size, const char **pp);