FFmpeg interface improvements

This patch changes a couple of things in the video output encoding.

{F362527}

- Clearer separation between container and codec. No more "format", as this is
  too ambiguous. As a result, codecs were removed from the container list.
- Added FFmpeg speed presets, so the user can choosen from the range "Very
  slow" to "Ultra fast". By default no preset is used.
- Added Constant Rate Factor (CRF) mode, which allows changing the bit-rate
  depending on the desired quality and the input. This generally produces the
  best quality videos, at the expense of not knowing the exact bit-rate and
  file size.
- Added optional maximum of non-B-frames between B-frames (`max_b_frames`).
- Presets were adjusted for these changes, and new presets added. One of the
  new presets is [recommended](https://trac.ffmpeg.org/wiki/Encode/VFX#H.264)
  for reviewing videos, as it allows players to scrub through it easily. Might
  be nice in weeklies. This preset also requires control over the
  `max_b_frames` setting.

GUI-only changes:
- Renamed "MPEG" in the output file format menu with "FFmpeg", as this is more
  accurate. After all, FFmpeg is used when this option is chosen, which can
  also output non-MPEG files.
- Certain parts of the GUI are disabled when not in use:
    - bit rate options are not used when a constant rate factor is given.
    - audio bitrate & volume are not used when no audio is exported.

Note that I did not touch `BKE_ffmpeg_preset_set()`. There are currently two
preset systems for FFmpeg (`BKE_ffmpeg_preset_set()` and the Python preset
system). Before we do more work on `BKE_ffmpeg_preset_set()`, I think it's a
good idea to determine whether we want to keep it at all.

After this patch has been accepted, I'd be happy to go through the code and
remove any then-obsolete bits, such as the handling of "XVID" as a container
format.

Reviewers: sergey, mont29, brecht

Subscribers: mpan3, Blendify, brecht, fsiddi

Tags: #bf_blender

Differential Revision: https://developer.blender.org/D2242

1 files changed, 14 insertions, 0 deletions

diff --git a/source/blender/blenloader/intern/versioning_270.c b/source/blender/blenloader/intern/versioning_270.c
index dfaa59c4e3f..aa5ef1c98cf 100644
--- a/source/blender/blenloader/intern/versioning_270.c
+++ b/source/blender/blenloader/intern/versioning_270.c
@@ -1392,4 +1392,18 @@ void blo_do_versions_270(FileData *fd, Library *UNUSED(lib), Main *main)
 			}
 		}
 	}
+	if (!MAIN_VERSION_ATLEAST(main, 279, 0)) {
+		if (!DNA_struct_elem_find(fd->filesdna, "FFMpegCodecData", "int", "ffmpeg_preset")) {
+			for (Scene *scene = main->scene.first; scene; scene = scene->id.next) {
+				/* "medium" is the preset FFmpeg uses when no presets are given. */
+				scene->r.ffcodecdata.ffmpeg_preset = FFM_PRESET_MEDIUM;
+			}
+		}
+		if (!DNA_struct_elem_find(fd->filesdna, "FFMpegCodecData", "int", "constant_rate_factor")) {
+			for (Scene *scene = main->scene.first; scene; scene = scene->id.next) {
+				/* fall back to behaviour from before we introduced CRF for old files */
+				scene->r.ffcodecdata.constant_rate_factor = FFM_CRF_NONE;
+			}
+		}
+	}
 }