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, 55 insertions, 21 deletions

diff --git a/source/blender/blenkernel/intern/writeffmpeg.c b/source/blender/blenkernel/intern/writeffmpeg.c
index de55a1977bf..b0ab6f707fa 100644
--- a/source/blender/blenkernel/intern/writeffmpeg.c
+++ b/source/blender/blenkernel/intern/writeffmpeg.c
@@ -69,10 +69,14 @@ typedef struct FFMpegContext {
 	int ffmpeg_video_bitrate;
 	int ffmpeg_audio_bitrate;
 	int ffmpeg_gop_size;
+	int ffmpeg_max_b_frames;
 	int ffmpeg_autosplit;
 	int ffmpeg_autosplit_count;
 	bool ffmpeg_preview;
 
+	int ffmpeg_crf;  /* set to 0 to not use CRF mode; we have another flag for lossless anyway. */
+	int ffmpeg_preset; /* see FFMpegPreset */
+
 	AVFormatContext *outfile;
 	AVStream *video_stream;
 	AVStream *audio_stream;
@@ -560,10 +564,37 @@ static AVStream *alloc_video_stream(FFMpegContext *context, RenderData *rd, int
 	}
 	
 	c->gop_size = context->ffmpeg_gop_size;
-	c->bit_rate = context->ffmpeg_video_bitrate * 1000;
-	c->rc_max_rate = rd->ffcodecdata.rc_max_rate * 1000;
-	c->rc_min_rate = rd->ffcodecdata.rc_min_rate * 1000;
-	c->rc_buffer_size = rd->ffcodecdata.rc_buffer_size * 1024;
+	c->max_b_frames = context->ffmpeg_max_b_frames;
+
+	if (context->ffmpeg_crf >= 0) {
+		ffmpeg_dict_set_int(&opts, "crf", context->ffmpeg_crf);
+	} else {
+		c->bit_rate = context->ffmpeg_video_bitrate * 1000;
+		c->rc_max_rate = rd->ffcodecdata.rc_max_rate * 1000;
+		c->rc_min_rate = rd->ffcodecdata.rc_min_rate * 1000;
+		c->rc_buffer_size = rd->ffcodecdata.rc_buffer_size * 1024;
+	}
+
+	if (context->ffmpeg_preset) {
+		char const * preset_name;
+		switch(context->ffmpeg_preset) {
+			case FFM_PRESET_ULTRAFAST: preset_name = "ultrafast"; break;
+			case FFM_PRESET_SUPERFAST: preset_name = "superfast"; break;
+			case FFM_PRESET_VERYFAST: preset_name = "veryfast"; break;
+			case FFM_PRESET_FASTER: preset_name = "faster"; break;
+			case FFM_PRESET_FAST: preset_name = "fast"; break;
+			case FFM_PRESET_MEDIUM: preset_name = "medium"; break;
+			case FFM_PRESET_SLOW: preset_name = "slow"; break;
+			case FFM_PRESET_SLOWER: preset_name = "slower"; break;
+			case FFM_PRESET_VERYSLOW: preset_name = "veryslow"; break;
+			default:
+				printf("Unknown preset number %i, ignoring.\n", context->ffmpeg_preset);
+				preset_name = NULL;
+		}
+		if (preset_name != NULL) {
+			av_dict_set(&opts, "preset", preset_name, 0);
+		}
+	}
 
 #if 0
 	/* this options are not set in ffmpeg.c and leads to artifacts with MPEG-4
@@ -819,6 +850,12 @@ static int start_ffmpeg_impl(FFMpegContext *context, struct RenderData *rd, int
 	context->ffmpeg_audio_bitrate = rd->ffcodecdata.audio_bitrate;
 	context->ffmpeg_gop_size = rd->ffcodecdata.gop_size;
 	context->ffmpeg_autosplit = rd->ffcodecdata.flags & FFMPEG_AUTOSPLIT_OUTPUT;
+	context->ffmpeg_crf = rd->ffcodecdata.constant_rate_factor;
+	context->ffmpeg_preset = rd->ffcodecdata.ffmpeg_preset;
+
+	if ((rd->ffcodecdata.flags & FFMPEG_USE_MAX_B_FRAMES) != 0) {
+		context->ffmpeg_max_b_frames = rd->ffcodecdata.max_b_frames;
+	}
 
 	/* Determine the correct filename */
 	ffmpeg_filepath_get(context, name, rd, context->ffmpeg_preview, suffix);
@@ -852,12 +889,16 @@ static int start_ffmpeg_impl(FFMpegContext *context, struct RenderData *rd, int
 	/* Returns after this must 'goto fail;' */
 
 	of->oformat = fmt;
-	of->packet_size = rd->ffcodecdata.mux_packet_size;
-	if (context->ffmpeg_audio_codec != AV_CODEC_ID_NONE) {
-		ffmpeg_dict_set_int(&opts, "muxrate", rd->ffcodecdata.mux_rate);
-	}
-	else {
-		av_dict_set(&opts, "muxrate", "0", 0);
+
+	/* Only bother with setting packet size & mux rate when CRF is not used. */
+	if (context->ffmpeg_crf == 0) {
+		of->packet_size = rd->ffcodecdata.mux_packet_size;
+		if (context->ffmpeg_audio_codec != AV_CODEC_ID_NONE) {
+			ffmpeg_dict_set_int(&opts, "muxrate", rd->ffcodecdata.mux_rate);
+		}
+		else {
+			av_dict_set(&opts, "muxrate", "0", 0);
+		}
 	}
 
 	ffmpeg_dict_set_int(&opts, "preload", (int)(0.5 * AV_TIME_BASE));
@@ -1503,14 +1544,6 @@ static void ffmpeg_set_expert_options(RenderData *rd)
 		BKE_ffmpeg_property_add_string(rd, "video", "fast-pskip:1");
 		BKE_ffmpeg_property_add_string(rd, "video", "wpredp:2");
 #endif
-
-		if (rd->ffcodecdata.flags & FFMPEG_LOSSLESS_OUTPUT) {
-#ifdef FFMPEG_HAVE_DEPRECATED_FLAGS2
-			BKE_ffmpeg_property_add_string(rd, "video", "cqp:0");
-#else
-			BKE_ffmpeg_property_add_string(rd, "video", "qp:0");
-#endif
-		}
 	}
 	else if (codec_id == AV_CODEC_ID_DNXHD) {
 		if (rd->ffcodecdata.flags & FFMPEG_LOSSLESS_OUTPUT)
@@ -1622,9 +1655,10 @@ void BKE_ffmpeg_image_type_verify(RenderData *rd, ImageFormatData *imf)
 		    rd->ffcodecdata.audio_codec <= 0 ||
 		    rd->ffcodecdata.video_bitrate <= 1)
 		{
-			rd->ffcodecdata.codec = AV_CODEC_ID_MPEG2VIDEO;
-
-			BKE_ffmpeg_preset_set(rd, FFMPEG_PRESET_DVD);
+			BKE_ffmpeg_preset_set(rd, FFMPEG_PRESET_H264);
+			rd->ffcodecdata.constant_rate_factor = FFM_CRF_MEDIUM;
+			rd->ffcodecdata.ffmpeg_preset = FFM_PRESET_MEDIUM;
+			rd->ffcodecdata.type = FFMPEG_MKV;
 		}
 		if (rd->ffcodecdata.type == FFMPEG_OGG) {
 			rd->ffcodecdata.type = FFMPEG_MPEG2;