import asyncio import json import logging import os import pathlib import re import shlex import shutil from lbry.conf import TranscodeConfig log = logging.getLogger(__name__) class VideoFileAnalyzer: def __init__(self, conf: TranscodeConfig): self._conf = conf self._available_encoders = "" self._ffmpeg_installed = False self._which = None async def _execute(self, command, arguments): args = shlex.split(arguments) process = await asyncio.create_subprocess_exec(self._conf.ffmpeg_folder + command, *args, stdout=asyncio.subprocess.PIPE, stderr=asyncio.subprocess.PIPE) stdout, stderr = await process.communicate() # returns when the streams are closed return stdout.decode(errors='replace') + stderr.decode(errors='replace'), process.returncode async def _verify_executable(self, name): try: version, code = await self._execute(name, "-version") except Exception as e: log.warning("Unable to run %s, but it was requested. Message: %s", name, str(e)) code = -1 version = "" if code != 0 or not version.startswith(name): raise FileNotFoundError(f"Unable to locate or run {name}. Please install FFmpeg " f"and ensure that it is callable via PATH or conf.ffmpeg_folder") return version async def _verify_ffmpeg_installed(self): if self._ffmpeg_installed: return await self._verify_executable("ffprobe") version = await self._verify_executable("ffmpeg") self._which = shutil.which(f"{self._conf.ffmpeg_folder}ffmpeg") self._ffmpeg_installed = True log.debug("Using %s at %s", version.splitlines()[0].split(" Copyright")[0], self._which) async def status(self, reset=False): if reset: self._available_encoders = "" self._ffmpeg_installed = False self._which = None installed = True try: await self._verify_ffmpeg_installed() except FileNotFoundError: installed = False return { "available": installed, "which": self._which, "analyze_audio_volume": int(self._conf.volume_analysis_time) > 0 } @staticmethod def _verify_container(scan_data: json): container = scan_data["format"]["format_name"] log.debug(" Detected container is %s", container) if not {"webm", "mp4", "3gp", "ogg"}.intersection(container.split(",")): return "Container format is not in the approved list of WebM, MP4. " \ f"Actual: {container} [{scan_data['format']['format_long_name']}]" return "" @staticmethod def _verify_video_encoding(scan_data: json): for stream in scan_data["streams"]: if stream["codec_type"] != "video": continue codec = stream["codec_name"] log.debug(" Detected video codec is %s, format is %s", codec, stream["pix_fmt"]) if not {"h264", "vp8", "vp9", "av1", "theora"}.intersection(codec.split(",")): return "Video codec is not in the approved list of H264, VP8, VP9, AV1, Theora. " \ f"Actual: {codec} [{stream['codec_long_name']}]" if "h264" in codec.split(",") and stream["pix_fmt"] != "yuv420p": return "Video codec is H264, but its pixel format does not match the approved yuv420p. " \ f"Actual: {stream['pix_fmt']}" return "" @staticmethod def _verify_bitrate(scan_data: json): if "bit_rate" not in scan_data["format"]: return "" bit_rate = float(scan_data["format"]["bit_rate"]) log.debug(" Detected bitrate is %s Mbps", str(bit_rate / 1000000.0)) pixels = -1.0 for stream in scan_data["streams"]: if stream["codec_type"] == "video": pieces = stream["r_frame_rate"].split('/', 1) frame_rate = float(pieces[0]) if len(pieces) == 1 \ else float(pieces[0]) / float(pieces[1]) pixels = max(pixels, float(stream["height"]) * float(stream["width"]) * frame_rate) if pixels > 0.0 and pixels / bit_rate < 3.0: return "Bits per second is excessive for this data; this may impact web streaming performance. " \ f"Actual: {str(bit_rate / 1000000.0)} Mbps" return "" async def _verify_fast_start(self, scan_data: json, video_file): container = scan_data["format"]["format_name"] if {"webm", "ogg"}.intersection(container.split(",")): return "" result, _ = await self._execute("ffprobe", f'-v debug "{video_file}"') match = re.search(r"Before avformat_find_stream_info.+?\s+seeks:(\d+)\s+", result) if match and int(match.group(1)) != 0: return "Video stream descriptors are not at the start of the file (the faststart flag was not used)." return "" @staticmethod def _verify_audio_encoding(scan_data: json): for stream in scan_data["streams"]: if stream["codec_type"] != "audio": continue codec = stream["codec_name"] log.debug(" Detected audio codec is %s", codec) if not {"aac", "mp3", "flac", "vorbis", "opus"}.intersection(codec.split(",")): return "Audio codec is not in the approved list of AAC, FLAC, MP3, Vorbis, and Opus. " \ f"Actual: {codec} [{stream['codec_long_name']}]" return "" async def _verify_audio_volume(self, seconds, video_file): try: validate_volume = int(seconds) > 0 except ValueError: validate_volume = False if not validate_volume: return "" result, _ = await self._execute("ffmpeg", f'-i "{video_file}" -t {seconds} ' f'-af volumedetect -vn -sn -dn -f null "{os.devnull}"') try: mean_volume = float(re.search(r"mean_volume:\s+([-+]?\d*\.\d+|\d+)", result).group(1)) max_volume = float(re.search(r"max_volume:\s+([-+]?\d*\.\d+|\d+)", result).group(1)) except Exception as e: log.debug(" Failure in volume analysis. Message: %s", str(e)) return "" if max_volume < -5.0 and mean_volume < -22.0: return "Audio is at least five dB lower than prime. " \ f"Actual max: {max_volume}, mean: {mean_volume}" log.debug(" Detected audio volume has mean, max of %f, %f dB", mean_volume, max_volume) return "" @staticmethod def _compute_crf(scan_data): height = 240.0 for stream in scan_data["streams"]: if stream["codec_type"] == "video": height = max(height, float(stream["height"])) # https://developers.google.com/media/vp9/settings/vod/ return int(-0.011 * height + 40) async def _get_video_encoder(self, scan_data): # use what the user said if it's there: # if it's not there, use h264 if we can because it's way faster than the others # if we don't have h264 use vp9; it's fairly compatible even though it's slow if not self._available_encoders: self._available_encoders, _ = await self._execute("ffmpeg", "-encoders -v quiet") encoder = self._conf.video_encoder.split(" ", 1)[0] if re.search(fr"^\s*V..... {encoder} ", self._available_encoders, re.MULTILINE): return self._conf.video_encoder if re.search(r"^\s*V..... libx264 ", self._available_encoders, re.MULTILINE): if encoder: log.warning(" Using libx264 since the requested encoder was unavailable. Requested: %s", encoder) return 'libx264 -crf 19 -vf "format=yuv420p"' if not encoder: encoder = "libx264" if re.search(r"^\s*V..... libvpx-vp9 ", self._available_encoders, re.MULTILINE): log.warning(" Using libvpx-vp9 since the requested encoder was unavailable. Requested: %s", encoder) crf = self._compute_crf(scan_data) return f"libvpx-vp9 -crf {crf} -b:v 0" if re.search(r"^\s*V..... libtheora", self._available_encoders, re.MULTILINE): log.warning(" Using libtheora since the requested encoder was unavailable. Requested: %s", encoder) return "libtheora -q:v 7" raise Exception(f"The video encoder is not available. Requested: {encoder}") async def _get_audio_encoder(self, extension): # if the video encoding is theora or av1/vp8/vp9 use opus (or fallback to vorbis) # or we don't have a video encoding but we have an ogg or webm container use opus # if we need to use opus/vorbis see if the conf file has it else use our own params # else use the user-set value if it exists # else use aac wants_opus = extension != "mp4" if not self._available_encoders: self._available_encoders, _ = await self._execute("ffmpeg", "-encoders -v quiet") encoder = self._conf.audio_encoder.split(" ", 1)[0] if wants_opus and 'opus' in encoder: return self._conf.audio_encoder if wants_opus and re.search(r"^\s*A..... libopus ", self._available_encoders, re.MULTILINE): return "libopus -b:a 160k" if wants_opus and 'vorbis' in encoder: return self._conf.audio_encoder if wants_opus and re.search(r"^\s*A..... libvorbis ", self._available_encoders, re.MULTILINE): return "libvorbis -q:a 6" if re.search(fr"^\s*A..... {encoder} ", self._available_encoders, re.MULTILINE): return self._conf.audio_encoder if re.search(r"^\s*A..... aac ", self._available_encoders, re.MULTILINE): return "aac -b:a 192k" raise Exception(f"The audio encoder is not available. Requested: {encoder or 'aac'}") async def _get_volume_filter(self): return self._conf.volume_filter if self._conf.volume_filter else "-af loudnorm" @staticmethod def _get_best_container_extension(scan_data, video_encoder): # the container is chosen by the video format # if we are theora-encoded, we want ogg # if we are vp8/vp9/av1 we want webm # use mp4 for anything else if not video_encoder: # not re-encoding video for stream in scan_data["streams"]: if stream["codec_type"] != "video": continue codec = stream["codec_name"].split(",") if "theora" in codec: return "ogg" if {"vp8", "vp9", "av1"}.intersection(codec): return "webm" if "theora" in video_encoder: return "ogg" elif re.search(r"vp[89x]|av1", video_encoder.split(" ", 1)[0]): return "webm" return "mp4" async def _get_scan_data(self, validate, file_path): result, _ = await self._execute("ffprobe", f'-v quiet -print_format json -show_format -show_streams "{file_path}"') try: scan_data = json.loads(result) except Exception as e: log.debug("Failure in JSON parsing ffprobe results. Message: %s", str(e)) if validate: raise Exception(f'Invalid video file: {file_path}') log.info("Unable to optimize %s . FFmpeg output was unreadable.", file_path) return if "format" not in scan_data: if validate: raise FileNotFoundError(f'Unexpected or absent video file contents at: {file_path}') log.info("Unable to optimize %s . FFmpeg output is missing the format section.", file_path) return return scan_data async def verify_or_repair(self, validate, repair, file_path): if not validate and not repair: return file_path await self._verify_ffmpeg_installed() scan_data = await self._get_scan_data(validate, file_path) fast_start_msg = await self._verify_fast_start(scan_data, file_path) log.debug("Analyzing %s:", file_path) log.debug(" Detected faststart is %s", "false" if fast_start_msg else "true") container_msg = self._verify_container(scan_data) bitrate_msg = self._verify_bitrate(scan_data) video_msg = self._verify_video_encoding(scan_data) audio_msg = self._verify_audio_encoding(scan_data) volume_msg = await self._verify_audio_volume(self._conf.volume_analysis_time, file_path) messages = [container_msg, bitrate_msg, fast_start_msg, video_msg, audio_msg, volume_msg] if not any(messages): return file_path if not repair: errors = ["Streamability verification failed:"] errors.extend(filter(None, messages)) raise Exception("\n ".join(errors)) # the plan for transcoding: # we have to re-encode the video if it is in a nonstandard format # we also re-encode if we are h264 but not yuv420p (both errors caught in video_msg) # we also re-encode if our bitrate is too high try: transcode_command = [f'-i "{file_path}" -y -c:s copy -c:d copy -c:v'] video_encoder = "" if video_msg or bitrate_msg: video_encoder = await self._get_video_encoder(scan_data) transcode_command.append(video_encoder) else: transcode_command.append("copy") transcode_command.append("-movflags +faststart -c:a") path = pathlib.Path(file_path) extension = self._get_best_container_extension(scan_data, video_encoder) if audio_msg or volume_msg: audio_encoder = await self._get_audio_encoder(extension) transcode_command.append(audio_encoder) if volume_msg: volume_filter = await self._get_volume_filter() transcode_command.append(volume_filter) else: transcode_command.append("copy") # TODO: put it in a temp folder and delete it after we upload? output = path.parent / f"{path.stem}_fixed.{extension}" transcode_command.append(f'"{output}"') ffmpeg_command = " ".join(transcode_command) log.info("Proceeding on transcode via: ffmpeg %s", ffmpeg_command) result, code = await self._execute("ffmpeg", ffmpeg_command) if code != 0: raise Exception(f"Failure to complete the transcode command. Output: {result}") except Exception as e: if validate: raise log.info("Unable to transcode %s . Message: %s", file_path, str(e)) # TODO: delete partial output file here if it exists? return file_path return str(output)