Convert HEVC to AIFC — Free Online Tool
Extract and convert audio from HEVC/H.265 video files into AIFC format using PCM 16-bit big-endian encoding — a lossless professional audio container developed by Apple. This tool is ideal when you need broadcast-quality, uncompressed audio from H.265 footage for use in Apple-native audio and video workflows.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
HEVC (.hevc) files contain only a raw H.265 video stream with no embedded audio track — they are a bare elementary video stream, not a container like MP4 or MKV. Because HEVC elementary streams carry no audio data, FFmpeg cannot copy or transcode any existing audio from them; instead, it generates silence or, more precisely, produces an AIFC output with an audio stream initialized to the default PCM codec (pcm_s16be). The output is an AIFC file — Apple's compressed/extended AIFF container — encoded with 16-bit signed big-endian PCM audio at 128k bitrate. AIFC uses big-endian byte ordering inherited from classic Mac hardware, which distinguishes it from WAV's little-endian PCM. No video stream is written to the output because AIFC is a pure audio container and cannot carry video.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg multimedia processing tool, which handles reading the raw HEVC elementary stream, performing the audio codec initialization, and writing the AIFC output container. |
-i input.hevc
|
Specifies the input file — a raw HEVC/H.265 elementary stream. Unlike container formats, .hevc files carry only compressed video bitstream data with no audio, metadata, or container structure beyond the NAL unit syntax. |
-c:a pcm_s16be
|
Sets the audio codec to 16-bit signed PCM in big-endian byte order, which is the native and default lossless audio encoding used by Apple's AIFC/AIFF container format — distinguishing it from WAV's little-endian PCM. |
-b:a 128k
|
Specifies a target audio bitrate of 128 kbps. For PCM codecs like pcm_s16be this value is effectively ignored since PCM bitrate is fixed by sample rate and bit depth, not a compression target — it is included as a default parameter and has no impact on output quality or file size. |
output.aifc
|
Defines the output filename with the .aifc extension, signaling FFmpeg to use the AIFC muxer — Apple's extended AIFF container that supports both uncompressed PCM and compressed audio codecs in a big-endian binary format. |
Common Use Cases
- Generating a silent or placeholder AIFC audio file timed to match the duration of a raw H.265 elementary stream for use as an audio reference track in Final Cut Pro or Logic Pro X projects
- Producing a PCM 16-bit big-endian AIFC file from an H.265 source for ingest into legacy Apple-based broadcast automation systems that require AIFC rather than WAV or AIFF
- Creating an AIFC audio shell from an HEVC clip to satisfy import requirements of older Avid or Pro Tools sessions that were authored on classic Mac hardware expecting big-endian PCM
- Converting an HEVC file's audio layer (if muxed into a renamed .hevc file) into a standalone AIFC track for archival in Apple-centric media asset management systems
- Extracting a silent AIFC spacer file with precise duration matching an H.265 video segment for multi-track audio timeline alignment in professional post-production environments
Frequently Asked Questions
Raw HEVC (.hevc) files are elementary video streams — they contain only compressed H.265 video data and carry absolutely no audio track. There is no audio to extract or transcode. The resulting AIFC file will either be silent or minimal depending on FFmpeg's behavior with the source. If your original file had audio, it was likely packaged in a container like .mp4 or .mkv with an .hevc extension, not a true elementary HEVC stream.
pcm_s16be stands for 16-bit signed PCM in big-endian byte order, which is the native encoding used by Apple's AIFF/AIFC format family originating from Motorola-based Mac hardware. Standard WAV files use pcm_s16le — the same bit depth but in little-endian byte order, native to Intel/x86 architecture. Both are lossless and sonically identical, but the byte ordering matters for compatibility with specific software and hardware that strictly validates the format.
AIFC (AIFF-C) is a superset of AIFF that was designed to support compressed audio codecs in addition to uncompressed PCM. When the codec is pcm_s16be, the AIFC file is functionally identical to a plain AIFF file and is fully compatible with modern Apple software including GarageBand, Logic Pro X, Final Cut Pro, and macOS's CoreAudio framework. Most professional DAWs on any platform also support AIFC without issue.
The -b:a 128k flag is included as a default parameter, but for lossless PCM codecs like pcm_s16be, bitrate targeting has no meaningful effect — PCM audio has a fixed, deterministic bitrate based on sample rate, bit depth, and channel count. The actual output bitrate will be calculated from those parameters (e.g., 44100 Hz stereo at 16-bit = ~1411 kbps), and the 128k value is effectively ignored by FFmpeg for PCM streams. You can omit it when running the command locally without any change to quality or output.
Replace -c:a pcm_s16be with -c:a pcm_s24be for 24-bit big-endian PCM, or -c:a pcm_s32be for 32-bit integer PCM — both are valid AIFC codecs and offer higher dynamic range for professional audio applications. For floating-point output, pcm_f32be (32-bit float) and pcm_f64be (64-bit double) are also supported in the AIFC container. For example: ffmpeg -i input.hevc -c:a pcm_s24be output.aifc
Yes. On Linux or macOS, you can run: for f in *.hevc; do ffmpeg -i "$f" -c:a pcm_s16be -b:a 128k "${f%.hevc}.aifc"; done. On Windows Command Prompt, use: for %f in (*.hevc) do ffmpeg -i "%f" -c:a pcm_s16be -b:a 128k "%~nf.aifc". This is particularly useful when processing raw HEVC elementary streams from camera systems that output individual clip files.
Technical Notes
HEVC elementary streams (.hevc) are a bare codec bitstream format — unlike MP4 or MKV containers, they have no container-level metadata, no audio tracks, no chapters, and no subtitle streams. This means the conversion to AIFC is essentially an audio-container generation operation rather than a true media transcode. AIFC itself imposes big-endian byte ordering on all PCM data, which is a holdover from the Motorola 68000 architecture of early Macintosh computers and is handled transparently by modern software. The AIFC container does not support video, multiple audio tracks, subtitles, or chapter markers, so none of the HEVC source's video data or HDR metadata (such as HDR10 or Dolby Vision signaling present in the H.265 stream) is preserved or referenced in the output. The -x265-params log-level=error flag suppresses verbose x265 encoder diagnostic output during processing, keeping the conversion clean without affecting output quality. Since pcm_s16be is lossless, the audio quality of any extracted audio is entirely source-dependent, and no generational quality loss occurs from the PCM encoding stage itself.