Deinterlacing and better filter logic

files/helpers.py

@@ -3,7 +3,6 @@
 
 import hashlib
 import json
-import math
 import os
 import random
 import shutil
@@ -245,6 +244,7 @@ def media_file_info(input_file):
     - `video_bitrate`: Bitrate of the video stream in kBit/s
     - `video_width`: Width in pixels
     - `video_height`: Height in pixels
+    - `interlaced` : True if the video is interlaced
     - `video_codec`: Video codec
     - `audio_duration`: Duration of the audio in `s.msec`
     - `audio_sample_rate`: Audio sample rate in Hz
@@ -369,16 +369,20 @@ def media_file_info(input_file):
         stdout = run_command(cmd).get("out")
         stream_size = sum([int(line) for line in stdout.split("\n") if line != ""])
         video_bitrate = round((stream_size * 8 / 1024.0) / video_duration, 2)
-    
-    if "r_frame_rate" in video_info.keys():   
+
+    if "r_frame_rate" in video_info.keys():
         video_frame_rate = video_info["r_frame_rate"].partition("/")
-        video_frame_rate_n =  video_frame_rate[0]
-        video_frame_rate_d =  video_frame_rate[2]  
+        video_frame_rate_n = video_frame_rate[0]
+        video_frame_rate_d = video_frame_rate[2]
+
+    interlaced = False
+    if video_info.get("field_order") in ("tt", "tb", "bt", "bb"):
+        interlaced = True
 
     ret = {
         "filename": input_file,
         "file_size": file_size,
-        "video_duration": video_duration, 
+        "video_duration": video_duration,
         "video_frame_rate_n": video_frame_rate_n,
         "video_frame_rate_d": video_frame_rate_d,
         "video_bitrate": video_bitrate,
@@ -387,13 +391,13 @@ def media_file_info(input_file):
         "video_codec": video_info["codec_name"],
         "has_video": has_video,
         "has_audio": has_audio,
-        "color_range": video_info["color_range"],
-        "color_space": video_info["color_space"],
+        "color_range": video_info.get("color_range"),
+        "color_space": video_info.get("color_space"),
         "color_transfer": video_info.get("color_space"),
         "color_primaries": video_info.get("color_primaries"),
-        "field_order": video_info["field_order"],
-        "display_aspect_ratio": video_info["display_aspect_ratio"],
-        "sample_aspect_ratio": video_info["sample_aspect_ratio"],
+        "interlaced": interlaced,
+        "display_aspect_ratio": video_info.get("display_aspect_ratio"),
+        "sample_aspect_ratio": video_info.get("sample_aspect_ratio"),
     }
 
     if has_audio:
@@ -491,6 +495,7 @@ def get_base_ffmpeg_command(
     encoder,
     audio_encoder,
     target_fps,
+    interlaced,
     target_height,
     target_rate,
     target_rate_audio,
@@ -509,6 +514,7 @@ def get_base_ffmpeg_command(
         encoder {str} -- video encoder
         audio_encoder {str} -- audio encoder
         target_fps {fractions.Fraction} -- target FPS
+        interlaced {bool} -- true if interlaced
         target_height {int} -- height
         target_rate {int} -- target bitrate in kbps
         target_rate_audio {int} -- audio target bitrate
@@ -519,11 +525,32 @@ def get_base_ffmpeg_command(
 
     # avoid very high frame rates
     while target_fps > 60:
-        target_fps = target_fps/2
+        target_fps = target_fps / 2
 
     if target_fps < 1:
         target_fps = 1
 
+    filters = []
+
+    if interlaced:
+        filters.append("yadif")
+
+    target_width = round(target_height * 16 / 9)
+    scale_filter_opts = [
+        f"if(lt(iw\\,ih)\\,{target_height}\\,{target_width})",
+        f"if(lt(iw\\,ih)\\,{target_width}\\,{target_height})",
+        "force_original_aspect_ratio=decrease",
+        "force_divisible_by=2",
+        "flags=lanczos",
+    ]
+    scale_filter_str = "scale=" + ":".join(scale_filter_opts)
+    filters.append(scale_filter_str)
+
+    fps_str = f"fps=fps={target_fps}"
+    filters.append(fps_str)
+
+    filters_str = ",".join(filters)
+
     base_cmd = [
         settings.FFMPEG_COMMAND,
         "-y",
@@ -532,9 +559,7 @@ def get_base_ffmpeg_command(
         "-c:v",
         encoder,
         "-filter:v",
-        "scale=-2:" + str(target_height) + ",fps=fps=" + str(target_fps),
-        # always convert to 4:2:0 -- FIXME: this could be also 4:2:2
-        # but compatibility will suffer
+        filters_str,
         "-pix_fmt",
         "yuv420p",
     ]
@@ -707,7 +732,6 @@ def produce_ffmpeg_commands(media_file, media_info, resolution, codec, output_fi
     #        target_fps = 25
     #    else:
 
-
     if media_info.get("video_duration") > CRF_ENCODING_NUM_SECONDS:
         enc_type = "crf"
     else:
@@ -718,6 +742,7 @@ def produce_ffmpeg_commands(media_file, media_info, resolution, codec, output_fi
     elif enc_type == "crf":
         passes = [2]
 
+    interlaced = media_info.get("interlaced")
 
     cmds = []
     for pass_number in passes:
@@ -730,6 +755,7 @@ def produce_ffmpeg_commands(media_file, media_info, resolution, codec, output_fi
                 encoder=encoder,
                 audio_encoder=AUDIO_ENCODERS[codec],
                 target_fps=target_fps,
+                interlaced=interlaced,
                 target_height=resolution,
                 target_rate=target_rate,
                 target_rate_audio=AUDIO_BITRATES[codec],
@@ -757,4 +783,4 @@ def clean_query(query):
     for char in chars:
         query = query.replace(char, "")
 
-    return query.lower()
+    return query.lower()