desktop.media.tomkv: add --rm-list-regen option, use tmp files for ff…

…mpeg output

desktop/media/tomkv

@@ -127,7 +127,11 @@ def main(args=None):
 			is larger than source*factor, otherwise destination.
 		Intended use is to make an easy-to-use list of files to
 			rm when replacing old ones with converted versions,
-			without unnecessary replacement if there's not enough benefit.'''))
+			without unnecessary replacement if there's not enough benefit.
+		File is always overwritten when used.'''))
+	parser.add_argument('--rm-list-regen', action='store_true', help=dd('''
+		When using -s/--skip-n or similar options,
+			still check file sizes when they exist, and put them on the list.'''))
 	parser.add_argument('-s', '--skip-n', metavar='n', type=int, help=dd('''
 		Skip first N files that'd have been processed otherwise.
 		Can be used to resume a long operation, using number from
@@ -189,7 +193,7 @@ def main(args=None):
 				for err in errs: print(f'  {err_verdict()} {err.get("t") or "-"} :: {err.msg}')
 			else: print(f'\n{dst} :: {err_verdict()} {err.get("t") or "-"} :: {err.msg}')
 			if skip: continue
-		src_list[n], p.src, p.dst = p, src, dst
+		src_list[n], p.src, p.dst, p.tmp = p, src, dst, f'_tmp.{dst}'
 
 	# Main ffmpeg conversion loop
 	dry_run, src_list = not opts.convert, list(filter(None, src_list))
@@ -211,10 +215,10 @@ def main(args=None):
 				'pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3'
 				'|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3,volume=2.0' ] + ac
 			elif p.a.chans != 2: ac = ['-ac', '2'] + ac
-		movflags = ( ['-movflags', '+faststart']
+		mov = ( ['-movflags', '+faststart']
 			if p.dst.rsplit('.', 1)[-1].lower() in ['mp4', 'mov', 'm4v'] else [] )
 		cmd = [ 'ffmpeg', '-hide_banner', '-i', str(p.src), *filters,
-			*'-c:v libsvtav1 -preset 5 -crf 38'.split(), *movflags, *ac, '-y', p.dst ]
+			*'-c:v libsvtav1 -preset 5 -crf 38'.split(), *mov, *ac, '-y', p.tmp ]
 		dt, ts1 = time.strftime('%Y-%m-%d %H:%M:%S'), time.monotonic()
 		msg = f'\n\n- {dt} --- [ {n} / {m} ] :: {td_repr(p.td)} :: {p.src} -> {p.dst}\n'
 		if n <= nx: continue
@@ -225,19 +229,26 @@ def main(args=None):
 
 		sp.run( cmd, check=True,
 			env=dict(os.environ, SVT_LOG='2'), stdin=sp.DEVNULL )
+		os.rename(p.tmp, p.dst)
 
-		# Per-file stats, compression check, rm-list export
+		# One-time stats/rm-list catch-up for skipped existing file pairs
 		if nx and (nd := n-nx) == 1:
-			for nc, pc in enumerate(src_list, 1): # add skipped dst-files into stats
+			for nc, pc in enumerate(src_list, 1):
 				if nc == n: break
-				try: sz_dst_done += os.stat(pc.dst).st_size; sz_src_done += pc.sz
-				except: pass
+				try: sz_dst = os.stat(pc.dst).st_size
+				except FileNotFoundError: continue
+				sz_dst_done += sz_dst; sz_src_done += (sz_src := pc.sz)
+				if rm_list and opts.rm_list_regen:
+					improved = sz_dst/sz_src < rm_list_factor
+					print(f'{pc.src if improved else pc.dst}\n', file=rm_list)
+
+		# Stats/rm-list for last processed file
 		target = ''
 		sz_src_done += (sz_src := p.sz); sz_src_proc += sz_src
 		sz_dst_done += (sz_dst := os.stat(p.dst).st_size)
 		if rm_list:
 			improved = sz_dst/sz_src < rm_list_factor
-			rm_list.write(f'{p.src if improved else p.dst}\n'); rm_list.flush()
+			print(f'{p.src if improved else p.dst}\n', file=rm_list, flush=True)
 			if rm_list_factor is not math.inf:
 				target = 'better' if improved else 'WORSE'
 				target = f' [ {target} than {round(rm_list_factor*100)}% target ]'