From: Jan Engelhardt <jengelh@inai.de>

​

Edit the default codec selection such that

​

    ffmpeg -i youtube.blah.webm foobar.mkv

​

without any further arguments can produce a result even on a

reduced codec selection list.

​

---

 libavformat/matroskaenc.c |   20 ++++++++++++++------

 1 file changed, 14 insertions(+), 6 deletions(-)

​

Index: ffmpeg-6.1.1/libavformat/matroskaenc.c

===================================================================

--- ffmpeg-6.1.1.orig/libavformat/matroskaenc.c

+++ ffmpeg-6.1.1/libavformat/matroskaenc.c

@@ -3538,16 +3538,25 @@ static int mkv_query_codec(enum AVCodecI

     return 0;

 }

+#define PREFAUDIO \

+   CONFIG_LIBOPUS_ENCODER ? AV_CODEC_ID_OPUS : \

+   CONFIG_AAC_ENCODER ? AV_CODEC_ID_AAC : \

+   CONFIG_VORBIS_ENCODER ? AV_CODEC_ID_VORBIS : \

+   AV_CODEC_ID_AC3

+

 const FFOutputFormat ff_matroska_muxer = {

     .p.name            = "matroska",

     .p.long_name       = NULL_IF_CONFIG_SMALL("Matroska"),

     .p.mime_type       = "video/x-matroska",

     .p.extensions      = "mkv",

     .priv_data_size    = sizeof(MatroskaMuxContext),

-    .p.audio_codec     = CONFIG_LIBVORBIS_ENCODER ?

-                         AV_CODEC_ID_VORBIS : AV_CODEC_ID_AC3,

-    .p.video_codec     = CONFIG_LIBX264_ENCODER ?

-                         AV_CODEC_ID_H264 : AV_CODEC_ID_MPEG4,

+    .p.audio_codec     = PREFAUDIO,

+    .p.video_codec     = 

+   CONFIG_LIBVPX_VP9_ENCODER ? AV_CODEC_ID_VP9 : \

+   CONFIG_LIBX264_ENCODER ? AV_CODEC_ID_H264 : \

+   CONFIG_LIBVPX_VP8_ENCODER ? AV_CODEC_ID_VP8 : \

+   CONFIG_MPEG4_ENCODER ? AV_CODEC_ID_MPEG4 : \

+   AV_CODEC_ID_THEORA,

     .init              = mkv_init,

     .deinit            = mkv_deinit,

     .write_header      = mkv_write_header,

@@ -3615,8 +3624,7 @@ const FFOutputFormat ff_matroska_audio_m

     .p.mime_type       = "audio/x-matroska",

     .p.extensions      = "mka",

     .priv_data_size    = sizeof(MatroskaMuxContext),

-    .p.audio_codec     = CONFIG_LIBVORBIS_ENCODER ?

-                         AV_CODEC_ID_VORBIS : AV_CODEC_ID_AC3,

+    .p.audio_codec     = PREFAUDIO,

     .p.video_codec     = AV_CODEC_ID_NONE,

     .init              = mkv_init,

     .deinit            = mkv_deinit,

​