ffmpeg_normalize

 51class FFmpegNormalize:
 52    """
 53    ffmpeg-normalize class.
 54
 55    Args:
 56        normalization_type (str, optional): Normalization type. Defaults to "ebu".
 57        target_level (float, optional): Target level. Defaults to -23.0.
 58        print_stats (bool, optional): Print loudnorm stats. Defaults to False.
 59        loudness_range_target (float, optional): Loudness range target. Defaults to 7.0.
 60        keep_loudness_range_target (bool, optional): Keep loudness range target. Defaults to False.
 61        keep_lra_above_loudness_range_target (bool, optional): Keep input loudness range above loudness range target. Defaults to False.
 62        true_peak (float, optional): True peak. Defaults to -2.0.
 63        offset (float, optional): Offset. Defaults to 0.0.
 64        lower_only (bool, optional): Whether the audio should not increase in loudness. Defaults to False.
 65        auto_lower_loudness_target (bool, optional): Automatically lower EBU Integrated Loudness Target.
 66        dual_mono (bool, optional): Dual mono. Defaults to False.
 67        dynamic (bool, optional): Dynamic. Defaults to False.
 68        audio_codec (str, optional): Audio codec. Defaults to "pcm_s16le".
 69        audio_bitrate (float, optional): Audio bitrate. Defaults to None.
 70        sample_rate (int, optional): Sample rate. Defaults to None.
 71        audio_channels (int | None, optional): Audio channels. Defaults to None.
 72        keep_original_audio (bool, optional): Keep original audio. Defaults to False.
 73        pre_filter (str, optional): Pre filter. Defaults to None.
 74        post_filter (str, optional): Post filter. Defaults to None.
 75        video_codec (str, optional): Video codec. Defaults to "copy".
 76        video_disable (bool, optional): Disable video. Defaults to False.
 77        subtitle_disable (bool, optional): Disable subtitles. Defaults to False.
 78        metadata_disable (bool, optional): Disable metadata. Defaults to False.
 79        chapters_disable (bool, optional): Disable chapters. Defaults to False.
 80        extra_input_options (list, optional): Extra input options. Defaults to None.
 81        extra_output_options (list, optional): Extra output options. Defaults to None.
 82        output_format (str, optional): Output format. Defaults to None.
 83        extension (str, optional): Output file extension to use for output files that were not explicitly specified. Defaults to "mkv".
 84        dry_run (bool, optional): Dry run. Defaults to False.
 85        debug (bool, optional): Debug. Defaults to False.
 86        progress (bool, optional): Progress. Defaults to False.
 87        replaygain (bool, optional): Write ReplayGain tags without normalizing. Defaults to False.
 88
 89    Raises:
 90        FFmpegNormalizeError: If the ffmpeg executable is not found or does not support the loudnorm filter.
 91    """
 92
 93    def __init__(
 94        self,
 95        normalization_type: Literal["ebu", "rms", "peak"] = "ebu",
 96        target_level: float = -23.0,
 97        print_stats: bool = False,
 98        # threshold=0.5,
 99        loudness_range_target: float = 7.0,
100        keep_loudness_range_target: bool = False,
101        keep_lra_above_loudness_range_target: bool = False,
102        true_peak: float = -2.0,
103        offset: float = 0.0,
104        lower_only: bool = False,
105        auto_lower_loudness_target: bool = False,
106        dual_mono: bool = False,
107        dynamic: bool = False,
108        audio_codec: str = "pcm_s16le",
109        audio_bitrate: float | None = None,
110        sample_rate: float | int | None = None,
111        audio_channels: int | None = None,
112        keep_original_audio: bool = False,
113        pre_filter: str | None = None,
114        post_filter: str | None = None,
115        video_codec: str = "copy",
116        video_disable: bool = False,
117        subtitle_disable: bool = False,
118        metadata_disable: bool = False,
119        chapters_disable: bool = False,
120        extra_input_options: list[str] | None = None,
121        extra_output_options: list[str] | None = None,
122        output_format: str | None = None,
123        extension: str = "mkv",
124        dry_run: bool = False,
125        debug: bool = False,
126        progress: bool = False,
127        replaygain: bool = False,
128    ):
129        self.ffmpeg_exe = get_ffmpeg_exe()
130        self.has_loudnorm_capabilities = ffmpeg_has_loudnorm()
131
132        if normalization_type not in NORMALIZATION_TYPES:
133            raise FFmpegNormalizeError(
134                "Normalization type must be: 'ebu', 'rms', or 'peak'"
135            )
136        self.normalization_type = normalization_type
137
138        if not self.has_loudnorm_capabilities and self.normalization_type == "ebu":
139            raise FFmpegNormalizeError(
140                "Your ffmpeg does not support the 'loudnorm' EBU R128 filter. "
141                "Please install ffmpeg v4.2 or above, or choose another normalization type."
142            )
143
144        if self.normalization_type == "ebu":
145            self.target_level = check_range(target_level, -70, -5, name="target_level")
146        else:
147            self.target_level = check_range(target_level, -99, 0, name="target_level")
148
149        self.print_stats = print_stats
150
151        # self.threshold = float(threshold)
152
153        self.loudness_range_target = check_range(
154            loudness_range_target, 1, 50, name="loudness_range_target"
155        )
156
157        self.keep_loudness_range_target = keep_loudness_range_target
158
159        if self.keep_loudness_range_target and loudness_range_target != 7.0:
160            _logger.warning(
161                "Setting --keep-loudness-range-target will override your set loudness range target value! "
162                "Remove --keep-loudness-range-target or remove the --lrt/--loudness-range-target option."
163            )
164
165        self.keep_lra_above_loudness_range_target = keep_lra_above_loudness_range_target
166
167        if (
168            self.keep_loudness_range_target
169            and self.keep_lra_above_loudness_range_target
170        ):
171            raise FFmpegNormalizeError(
172                "Options --keep-loudness-range-target and --keep-lra-above-loudness-range-target are mutually exclusive! "
173                "Please choose just one of the two options."
174            )
175
176        self.true_peak = check_range(true_peak, -9, 0, name="true_peak")
177        self.offset = check_range(offset, -99, 99, name="offset")
178        self.lower_only = lower_only
179        self.auto_lower_loudness_target = auto_lower_loudness_target
180
181        # Ensure library user is passing correct types
182        assert isinstance(dual_mono, bool), "dual_mono must be bool"
183        assert isinstance(dynamic, bool), "dynamic must be bool"
184
185        self.dual_mono = dual_mono
186        self.dynamic = dynamic
187        self.sample_rate = None if sample_rate is None else int(sample_rate)
188        self.audio_channels = None if audio_channels is None else int(audio_channels)
189
190        self.audio_codec = audio_codec
191        self.audio_bitrate = audio_bitrate
192        self.keep_original_audio = keep_original_audio
193        self.video_codec = video_codec
194        self.video_disable = video_disable
195        self.subtitle_disable = subtitle_disable
196        self.metadata_disable = metadata_disable
197        self.chapters_disable = chapters_disable
198
199        self.extra_input_options = extra_input_options
200        self.extra_output_options = extra_output_options
201        self.pre_filter = pre_filter
202        self.post_filter = post_filter
203
204        self.output_format = output_format
205        self.extension = extension
206        self.dry_run = dry_run
207        self.debug = debug
208        self.progress = progress
209        self.replaygain = replaygain
210
211        if (
212            self.audio_codec is None or "pcm" in self.audio_codec
213        ) and self.output_format in PCM_INCOMPATIBLE_FORMATS:
214            raise FFmpegNormalizeError(
215                f"Output format {self.output_format} does not support PCM audio. "
216                "Please choose a suitable audio codec with the -c:a option."
217            )
218
219        # replaygain only works for EBU for now
220        if self.replaygain and self.normalization_type != "ebu":
221            raise FFmpegNormalizeError(
222                "ReplayGain only works for EBU normalization type for now."
223            )
224
225        self.stats: list[LoudnessStatisticsWithMetadata] = []
226        self.media_files: list[MediaFile] = []
227        self.file_count = 0
228
229    def add_media_file(self, input_file: str, output_file: str) -> None:
230        """
231        Add a media file to normalize
232
233        Args:
234            input_file (str): Path to input file
235            output_file (str): Path to output file
236        """
237        if not os.path.exists(input_file):
238            raise FFmpegNormalizeError(f"file {input_file} does not exist")
239
240        ext = os.path.splitext(output_file)[1][1:]
241        if (
242            self.audio_codec is None or "pcm" in self.audio_codec
243        ) and ext in PCM_INCOMPATIBLE_EXTS:
244            raise FFmpegNormalizeError(
245                f"Output extension {ext} does not support PCM audio. "
246                "Please choose a suitable audio codec with the -c:a option."
247            )
248
249        self.media_files.append(MediaFile(self, input_file, output_file))
250        self.file_count += 1
251
252    def run_normalization(self) -> None:
253        """
254        Run the normalization procedures
255        """
256        for index, media_file in enumerate(
257            tqdm(self.media_files, desc="File", disable=not self.progress, position=0)
258        ):
259            _logger.info(
260                f"Normalizing file {media_file} ({index + 1} of {self.file_count})"
261            )
262
263            try:
264                media_file.run_normalization()
265            except Exception as e:
266                if len(self.media_files) > 1:
267                    # simply warn and do not die
268                    _logger.error(
269                        f"Error processing input file {media_file}, will "
270                        f"continue batch-processing. Error was: {e}"
271                    )
272                else:
273                    # raise the error so the program will exit
274                    raise e
275
276        if self.print_stats:
277            json.dump(
278                list(
279                    chain.from_iterable(
280                        media_file.get_stats() for media_file in self.media_files
281                    )
282                ),
283                sys.stdout,
284                indent=4,
285            )
286            print()

2class FFmpegNormalizeError(Exception):
3    pass

 56class MediaFile:
 57    """
 58    Class that holds a file, its streams and adjustments
 59    """
 60
 61    def __init__(
 62        self, ffmpeg_normalize: FFmpegNormalize, input_file: str, output_file: str
 63    ):
 64        """
 65        Initialize a media file for later normalization by parsing the streams.
 66
 67        Args:
 68            ffmpeg_normalize (FFmpegNormalize): reference to overall settings
 69            input_file (str): Path to input file
 70            output_file (str): Path to output file
 71        """
 72        self.ffmpeg_normalize = ffmpeg_normalize
 73        self.skip = False
 74        self.input_file = input_file
 75        self.output_file = output_file
 76        current_ext = os.path.splitext(output_file)[1][1:]
 77        # we need to check if it's empty, e.g. /dev/null or NUL
 78        if current_ext == "" or self.output_file == os.devnull:
 79            _logger.debug(
 80                f"Current extension is unset, or output file is a null device, using extension: {self.ffmpeg_normalize.extension}"
 81            )
 82            self.output_ext = self.ffmpeg_normalize.extension
 83        else:
 84            _logger.debug(
 85                f"Current extension is set from output file, using extension: {current_ext}"
 86            )
 87            self.output_ext = current_ext
 88        self.streams: StreamDict = {"audio": {}, "video": {}, "subtitle": {}}
 89        self.temp_file: Union[str, None] = None
 90
 91        self.parse_streams()
 92
 93    def _stream_ids(self) -> list[int]:
 94        """
 95        Get all stream IDs of this file.
 96
 97        Returns:
 98            list: List of stream IDs
 99        """
100        return (
101            list(self.streams["audio"].keys())
102            + list(self.streams["video"].keys())
103            + list(self.streams["subtitle"].keys())
104        )
105
106    def __repr__(self) -> str:
107        return os.path.basename(self.input_file)
108
109    def parse_streams(self) -> None:
110        """
111        Try to parse all input streams from file and set them in self.streams.
112
113        Raises:
114            FFmpegNormalizeError: If no audio streams are found
115        """
116        _logger.debug(f"Parsing streams of {self.input_file}")
117
118        cmd = [
119            self.ffmpeg_normalize.ffmpeg_exe,
120            "-i",
121            self.input_file,
122            "-c",
123            "copy",
124            "-t",
125            "0",
126            "-map",
127            "0",
128            "-f",
129            "null",
130            os.devnull,
131        ]
132
133        output = CommandRunner().run_command(cmd).get_output()
134
135        _logger.debug("Stream parsing command output:")
136        _logger.debug(output)
137
138        output_lines = [line.strip() for line in output.split("\n")]
139
140        duration = None
141        for line in output_lines:
142            if "Duration" in line:
143                if duration_search := DUR_REGEX.search(line):
144                    duration = _to_ms(**duration_search.groupdict()) / 1000
145                    _logger.debug(f"Found duration: {duration} s")
146                else:
147                    _logger.warning("Could not extract duration from input file!")
148
149            if not line.startswith("Stream"):
150                continue
151
152            if stream_id_match := re.search(r"#0:([\d]+)", line):
153                stream_id = int(stream_id_match.group(1))
154                if stream_id in self._stream_ids():
155                    continue
156            else:
157                continue
158
159            if "Audio" in line:
160                _logger.debug(f"Found audio stream at index {stream_id}")
161                sample_rate_match = re.search(r"(\d+) Hz", line)
162                sample_rate = (
163                    int(sample_rate_match.group(1)) if sample_rate_match else None
164                )
165                bit_depth_match = re.search(r"[sfu](\d+)(p|le|be)?", line)
166                bit_depth = int(bit_depth_match.group(1)) if bit_depth_match else None
167                self.streams["audio"][stream_id] = AudioStream(
168                    self.ffmpeg_normalize,
169                    self,
170                    stream_id,
171                    sample_rate,
172                    bit_depth,
173                    duration,
174                )
175
176            elif "Video" in line:
177                _logger.debug(f"Found video stream at index {stream_id}")
178                self.streams["video"][stream_id] = VideoStream(
179                    self.ffmpeg_normalize, self, stream_id
180                )
181
182            elif "Subtitle" in line:
183                _logger.debug(f"Found subtitle stream at index {stream_id}")
184                self.streams["subtitle"][stream_id] = SubtitleStream(
185                    self.ffmpeg_normalize, self, stream_id
186                )
187
188        if not self.streams["audio"]:
189            raise FFmpegNormalizeError(
190                f"Input file {self.input_file} does not contain any audio streams"
191            )
192
193        if (
194            self.output_ext.lower() in ONE_STREAM
195            and len(self.streams["audio"].values()) > 1
196        ):
197            _logger.warning(
198                "Output file only supports one stream. Keeping only first audio stream."
199            )
200            first_stream = list(self.streams["audio"].values())[0]
201            self.streams["audio"] = {first_stream.stream_id: first_stream}
202            self.streams["video"] = {}
203            self.streams["subtitle"] = {}
204
205    def run_normalization(self) -> None:
206        """
207        Run the normalization process for this file.
208        """
209        _logger.debug(f"Running normalization for {self.input_file}")
210
211        # run the first pass to get loudness stats
212        self._first_pass()
213
214        # for second pass, create a temp file
215        temp_dir = mkdtemp()
216        self.temp_file = os.path.join(temp_dir, f"out.{self.output_ext}")
217
218        if self.ffmpeg_normalize.replaygain:
219            _logger.debug(
220                "ReplayGain mode: Second pass will run with temporary file to get stats."
221            )
222            self.output_file = self.temp_file
223
224        # run the second pass as a whole.
225        if self.ffmpeg_normalize.progress:
226            with tqdm(
227                total=100,
228                position=1,
229                desc="Second Pass",
230                bar_format=TQDM_BAR_FORMAT,
231            ) as pbar:
232                for progress in self._second_pass():
233                    pbar.update(progress - pbar.n)
234        else:
235            for _ in self._second_pass():
236                pass
237
238        # remove temp dir; this will remove the temp file as well if it has not been renamed (e.g. for replaygain)
239        if os.path.exists(temp_dir):
240            rmtree(temp_dir, ignore_errors=True)
241
242        # This will use stats from ebu_pass2 if available (from the main second pass),
243        # or fall back to ebu_pass1.
244        if self.ffmpeg_normalize.replaygain:
245            _logger.debug(
246                "ReplayGain tagging is enabled. Proceeding with tag calculation/application."
247            )
248            self._run_replaygain()
249
250        if not self.ffmpeg_normalize.replaygain:
251            _logger.info(f"Normalized file written to {self.output_file}")
252
253    def _run_replaygain(self) -> None:
254        """
255        Run the replaygain process for this file.
256        """
257        _logger.debug(f"Running replaygain for {self.input_file}")
258
259        # get the audio streams
260        audio_streams = list(self.streams["audio"].values())
261
262        # Attempt to use EBU pass 2 statistics, which account for pre-filters.
263        # These are populated by the main second pass if it runs (not a dry run)
264        # and normalization_type is 'ebu'.
265        loudness_stats_source = "ebu_pass2"
266        loudnorm_stats = audio_streams[0].loudness_statistics.get("ebu_pass2")
267
268        if loudnorm_stats is None:
269            _logger.warning(
270                "ReplayGain: Second pass EBU statistics (ebu_pass2) not found. "
271                "Falling back to first pass EBU statistics (ebu_pass1). "
272                "This may not account for pre-filters if any are used."
273            )
274            loudness_stats_source = "ebu_pass1"
275            loudnorm_stats = audio_streams[0].loudness_statistics.get("ebu_pass1")
276
277        if loudnorm_stats is None:
278            _logger.error(
279                f"ReplayGain: No loudness statistics available from {loudness_stats_source} (and fallback) for stream 0. "
280                "Cannot calculate ReplayGain tags."
281            )
282            return
283
284        _logger.debug(
285            f"Using statistics from {loudness_stats_source} for ReplayGain calculation."
286        )
287
288        # apply the replaygain tag from the first audio stream (to all audio streams)
289        if len(audio_streams) > 1:
290            _logger.warning(
291                f"Your input file has {len(audio_streams)} audio streams. "
292                "Only the first audio stream's replaygain tag will be applied. "
293                "All audio streams will receive the same tag."
294            )
295
296        target_level = self.ffmpeg_normalize.target_level
297        # Use 'input_i' and 'input_tp' from the chosen stats.
298        # For ebu_pass2, these are measurements *after* pre-filter but *before* loudnorm adjustment.
299        input_i = loudnorm_stats.get("input_i")
300        input_tp = loudnorm_stats.get("input_tp")
301
302        if input_i is None or input_tp is None:
303            _logger.error(
304                f"ReplayGain: 'input_i' or 'input_tp' missing from {loudness_stats_source} statistics. "
305                "Cannot calculate ReplayGain tags."
306            )
307            return
308
309        track_gain = -(input_i - target_level)  # dB
310        track_peak = 10 ** (input_tp / 20)  # linear scale
311
312        _logger.debug(f"Calculated Track gain: {track_gain:.2f} dB")
313        _logger.debug(f"Calculated Track peak: {track_peak:.2f}")
314
315        if not self.ffmpeg_normalize.dry_run:  # This uses the overall dry_run state
316            self._write_replaygain_tags(track_gain, track_peak)
317        else:
318            _logger.warning(
319                "Overall dry_run is enabled, not actually writing ReplayGain tags to the file. "
320                "Tag calculation based on available stats was performed."
321            )
322
323    def _write_replaygain_tags(self, track_gain: float, track_peak: float) -> None:
324        """
325        Write the replaygain tags to the input file.
326
327        This is based on the code from bohning/usdb_syncer, licensed under the MIT license.
328        See: https://github.com/bohning/usdb_syncer/blob/2fa638c4f487dffe9f5364f91e156ba54cb20233/src/usdb_syncer/resource_dl.py
329        """
330        _logger.debug(f"Writing ReplayGain tags to {self.input_file}")
331
332        input_file_ext = os.path.splitext(self.input_file)[1]
333        if input_file_ext == ".mp3":
334            mp3 = MP3(self.input_file, ID3=ID3)
335            if not mp3.tags:
336                return
337            mp3.tags.add(
338                TXXX(desc="REPLAYGAIN_TRACK_GAIN", text=[f"{track_gain:.2f} dB"])
339            )
340            mp3.tags.add(TXXX(desc="REPLAYGAIN_TRACK_PEAK", text=[f"{track_peak:.6f}"]))
341            mp3.save()
342        elif input_file_ext in [".mp4", ".m4a", ".m4v", ".mov"]:
343            mp4 = MP4(self.input_file)
344            if not mp4.tags:
345                mp4.add_tags()
346            if not mp4.tags:
347                return
348            mp4.tags["----:com.apple.iTunes:REPLAYGAIN_TRACK_GAIN"] = [
349                f"{track_gain:.2f} dB".encode()
350            ]
351            mp4.tags["----:com.apple.iTunes:REPLAYGAIN_TRACK_PEAK"] = [
352                f"{track_peak:.6f}".encode()
353            ]
354            mp4.save()
355        elif input_file_ext == ".ogg":
356            ogg = OggVorbis(self.input_file)
357            ogg["REPLAYGAIN_TRACK_GAIN"] = [f"{track_gain:.2f} dB"]
358            ogg["REPLAYGAIN_TRACK_PEAK"] = [f"{track_peak:.6f}"]
359            ogg.save()
360        elif input_file_ext == ".opus":
361            opus = OggOpus(self.input_file)
362            # See https://datatracker.ietf.org/doc/html/rfc7845#section-5.2.1
363            opus["R128_TRACK_GAIN"] = [str(round(256 * track_gain))]
364            opus.save()
365        else:
366            _logger.error(
367                f"Unsupported input file extension: {input_file_ext} for writing replaygain tags. "
368                "Only .mp3, .mp4/.m4a, .ogg, .opus are supported. "
369                "If you think this should support more formats, please let me know at "
370                "https://github.com/slhck/ffmpeg-normalize/issues"
371            )
372            return
373
374        _logger.info(
375            f"Successfully wrote replaygain tags to input file {self.input_file}"
376        )
377
378    def _can_write_output_video(self) -> bool:
379        """
380        Determine whether the output file can contain video at all.
381
382        Returns:
383            bool: True if the output file can contain video, False otherwise
384        """
385        if self.output_ext.lower() in AUDIO_ONLY_FORMATS:
386            return False
387
388        return not self.ffmpeg_normalize.video_disable
389
390    def _first_pass(self) -> None:
391        """
392        Run the first pass of the normalization process.
393        """
394        _logger.debug(f"Parsing normalization info for {self.input_file}")
395
396        for index, audio_stream in enumerate(self.streams["audio"].values()):
397            if self.ffmpeg_normalize.normalization_type == "ebu":
398                fun = getattr(audio_stream, "parse_loudnorm_stats")
399            else:
400                fun = getattr(audio_stream, "parse_astats")
401
402            if self.ffmpeg_normalize.progress:
403                with tqdm(
404                    total=100,
405                    position=1,
406                    desc=f"Stream {index + 1}/{len(self.streams['audio'].values())}",
407                    bar_format=TQDM_BAR_FORMAT,
408                ) as pbar:
409                    for progress in fun():
410                        pbar.update(progress - pbar.n)
411            else:
412                for _ in fun():
413                    pass
414
415    def _get_audio_filter_cmd(self) -> tuple[str, list[str]]:
416        """
417        Return the audio filter command and output labels needed.
418
419        Returns:
420            tuple[str, list[str]]: filter_complex command and the required output labels
421        """
422        filter_chains = []
423        output_labels = []
424
425        for audio_stream in self.streams["audio"].values():
426            skip_normalization = False
427            if self.ffmpeg_normalize.lower_only:
428                if self.ffmpeg_normalize.normalization_type == "ebu":
429                    if (
430                        audio_stream.loudness_statistics["ebu_pass1"] is not None
431                        and audio_stream.loudness_statistics["ebu_pass1"]["input_i"]
432                        < self.ffmpeg_normalize.target_level
433                    ):
434                        skip_normalization = True
435                elif self.ffmpeg_normalize.normalization_type == "peak":
436                    if (
437                        audio_stream.loudness_statistics["max"] is not None
438                        and audio_stream.loudness_statistics["max"]
439                        < self.ffmpeg_normalize.target_level
440                    ):
441                        skip_normalization = True
442                elif self.ffmpeg_normalize.normalization_type == "rms":
443                    if (
444                        audio_stream.loudness_statistics["mean"] is not None
445                        and audio_stream.loudness_statistics["mean"]
446                        < self.ffmpeg_normalize.target_level
447                    ):
448                        skip_normalization = True
449
450            if skip_normalization:
451                _logger.warning(
452                    f"Stream {audio_stream.stream_id} had measured input loudness lower than target, skipping normalization."
453                )
454                normalization_filter = "acopy"
455            else:
456                if self.ffmpeg_normalize.normalization_type == "ebu":
457                    normalization_filter = audio_stream.get_second_pass_opts_ebu()
458                else:
459                    normalization_filter = audio_stream.get_second_pass_opts_peakrms()
460
461            input_label = f"[0:{audio_stream.stream_id}]"
462            output_label = f"[norm{audio_stream.stream_id}]"
463            output_labels.append(output_label)
464
465            filter_chain = []
466
467            if self.ffmpeg_normalize.pre_filter:
468                filter_chain.append(self.ffmpeg_normalize.pre_filter)
469
470            filter_chain.append(normalization_filter)
471
472            if self.ffmpeg_normalize.post_filter:
473                filter_chain.append(self.ffmpeg_normalize.post_filter)
474
475            filter_chains.append(input_label + ",".join(filter_chain) + output_label)
476
477        filter_complex_cmd = ";".join(filter_chains)
478
479        return filter_complex_cmd, output_labels
480
481    def _second_pass(self) -> Iterator[float]:
482        """
483        Construct the second pass command and run it.
484
485        FIXME: make this method simpler
486        """
487        _logger.info(f"Running second pass for {self.input_file}")
488
489        # get the target output stream types depending on the options
490        output_stream_types: list[Literal["audio", "video", "subtitle"]] = ["audio"]
491        if self._can_write_output_video():
492            output_stream_types.append("video")
493        if not self.ffmpeg_normalize.subtitle_disable:
494            output_stream_types.append("subtitle")
495
496        # base command, here we will add all other options
497        cmd = [self.ffmpeg_normalize.ffmpeg_exe, "-hide_banner", "-y"]
498
499        # extra options (if any)
500        if self.ffmpeg_normalize.extra_input_options:
501            cmd.extend(self.ffmpeg_normalize.extra_input_options)
502
503        # get complex filter command
504        audio_filter_cmd, output_labels = self._get_audio_filter_cmd()
505
506        # add input file and basic filter
507        cmd.extend(["-i", self.input_file, "-filter_complex", audio_filter_cmd])
508
509        # map metadata, only if needed
510        if self.ffmpeg_normalize.metadata_disable:
511            cmd.extend(["-map_metadata", "-1"])
512        else:
513            # map global metadata
514            cmd.extend(["-map_metadata", "0"])
515            # map per-stream metadata (e.g. language tags)
516            for stream_type in output_stream_types:
517                stream_key = stream_type[0]
518                if stream_type not in self.streams:
519                    continue
520                for idx, _ in enumerate(self.streams[stream_type].items()):
521                    cmd.extend(
522                        [
523                            f"-map_metadata:s:{stream_key}:{idx}",
524                            f"0:s:{stream_key}:{idx}",
525                        ]
526                    )
527
528        # map chapters if needed
529        if self.ffmpeg_normalize.chapters_disable:
530            cmd.extend(["-map_chapters", "-1"])
531        else:
532            cmd.extend(["-map_chapters", "0"])
533
534        # collect all '-map' and codecs needed for output video based on input video
535        if self.streams["video"]:
536            if self._can_write_output_video():
537                for s in self.streams["video"].keys():
538                    cmd.extend(["-map", f"0:{s}"])
539                # set codec (copy by default)
540                cmd.extend(["-c:v", self.ffmpeg_normalize.video_codec])
541            else:
542                if not self.ffmpeg_normalize.video_disable:
543                    _logger.warning(
544                        f"The chosen output extension {self.output_ext} does not support video/cover art. It will be disabled."
545                    )
546
547        # ... and map the output of the normalization filters
548        for ol in output_labels:
549            cmd.extend(["-map", ol])
550
551        # set audio codec (never copy)
552        if self.ffmpeg_normalize.audio_codec:
553            cmd.extend(["-c:a", self.ffmpeg_normalize.audio_codec])
554        else:
555            for index, (_, audio_stream) in enumerate(self.streams["audio"].items()):
556                cmd.extend([f"-c:a:{index}", audio_stream.get_pcm_codec()])
557
558        # other audio options (if any)
559        if self.ffmpeg_normalize.audio_bitrate:
560            if self.ffmpeg_normalize.audio_codec == "libvorbis":
561                # libvorbis takes just a "-b" option, for some reason
562                # https://github.com/slhck/ffmpeg-normalize/issues/277
563                cmd.extend(["-b", str(self.ffmpeg_normalize.audio_bitrate)])
564            else:
565                cmd.extend(["-b:a", str(self.ffmpeg_normalize.audio_bitrate)])
566        if self.ffmpeg_normalize.sample_rate:
567            cmd.extend(["-ar", str(self.ffmpeg_normalize.sample_rate)])
568        if self.ffmpeg_normalize.audio_channels:
569            cmd.extend(["-ac", str(self.ffmpeg_normalize.audio_channels)])
570
571        # ... and subtitles
572        if not self.ffmpeg_normalize.subtitle_disable:
573            for s in self.streams["subtitle"].keys():
574                cmd.extend(["-map", f"0:{s}"])
575            # copy subtitles
576            cmd.extend(["-c:s", "copy"])
577
578        if self.ffmpeg_normalize.keep_original_audio:
579            highest_index = len(self.streams["audio"])
580            for index, _ in enumerate(self.streams["audio"].items()):
581                cmd.extend(["-map", f"0:a:{index}"])
582                cmd.extend([f"-c:a:{highest_index + index}", "copy"])
583
584        # extra options (if any)
585        if self.ffmpeg_normalize.extra_output_options:
586            cmd.extend(self.ffmpeg_normalize.extra_output_options)
587
588        # output format (if any)
589        if self.ffmpeg_normalize.output_format:
590            cmd.extend(["-f", self.ffmpeg_normalize.output_format])
591
592        # if dry run, only show sample command
593        if self.ffmpeg_normalize.dry_run:
594            cmd.append(self.output_file)
595            _logger.warning("Dry run used, not actually running second-pass command")
596            CommandRunner(dry=True).run_command(cmd)
597            yield 100
598            return
599
600        # special case: if output is a null device, write directly to it
601        if self.output_file == os.devnull:
602            cmd.append(self.output_file)
603        else:
604            temp_dir = mkdtemp()
605            temp_file = os.path.join(temp_dir, f"out.{self.output_ext}")
606            cmd.append(temp_file)
607
608        cmd_runner = CommandRunner()
609        try:
610            yield from cmd_runner.run_ffmpeg_command(cmd)
611        except Exception as e:
612            _logger.error(f"Error while running command {shlex.join(cmd)}! Error: {e}")
613            raise e
614        else:
615            # only move the temp file if it's not a null device and ReplayGain is not enabled!
616            if self.output_file != os.devnull and not self.ffmpeg_normalize.replaygain:
617                _logger.debug(
618                    f"Moving temporary file from {temp_file} to {self.output_file}"
619                )
620                move(temp_file, self.output_file)
621
622        output = cmd_runner.get_output()
623        # in the second pass, we do not normalize stream-by-stream, so we set the stats based on the
624        # overall output (which includes multiple loudnorm stats)
625        if self.ffmpeg_normalize.normalization_type == "ebu":
626            ebu_pass_2_stats = list(
627                AudioStream.prune_and_parse_loudnorm_output(output).values()
628            )
629            for idx, audio_stream in enumerate(self.streams["audio"].values()):
630                audio_stream.set_second_pass_stats(ebu_pass_2_stats[idx])
631
632        # warn if self.media_file.ffmpeg_normalize.dynamic == False and any of the second pass stats contain "normalization_type" == "dynamic"
633        if self.ffmpeg_normalize.dynamic is False:
634            for audio_stream in self.streams["audio"].values():
635                pass2_stats = audio_stream.get_stats()["ebu_pass2"]
636                if pass2_stats is None:
637                    continue
638                if pass2_stats["normalization_type"] == "dynamic":
639                    _logger.warning(
640                        "You specified linear normalization, but the loudnorm filter reverted to dynamic normalization. "
641                        "This may lead to unexpected results."
642                        "Consider your input settings, e.g. choose a lower target level or higher target loudness range."
643                    )
644
645        _logger.debug("Normalization finished")
646
647    def get_stats(self) -> Iterable[LoudnessStatisticsWithMetadata]:
648        return (
649            audio_stream.get_stats() for audio_stream in self.streams["audio"].values()
650        )