[FFmpeg-devel] [PATCH] avformat/wavenc: use RF64 when needed

[FFmpeg-devel] [PATCH] avformat/wavenc: use RF64 when needed

[Jason A. Donenfeld via ffmpeg-devel]

Currently if you encode a large wav, ffmpeg will hint after the fact
that the resultant file is corrupted, because traditional wav cannot
handle lengths greater than 32-bits. This isn't very useful; nobody
benefits from getting garbage files.

You can manually work around this by adding `-rf64 always`, which most
players have support for. Most people don't remember to do this until
after the fact when their file is corrupted, or they don't figure it out
at all and wind up using the w64 container instead.

And so that's what `-rf64 auto` is for. It uses the larger format when
needed, and if not, uses the traditional wav that is probably more
compatible. The result of using `-rf64 auto` is that you can add it to
every command line -- and should add it to every command line -- to get
either a normal small file, or a non-corrupt large file.

This is a very sensible default to have on, rather than just producing
corrupt files and having users scrambling for solutions, and then having
to do a potentially expensive reencode after. With `-rf64 auto` on by
default, the user always gets a readable good file. And for users who
sometimes want corrupt files, there still exists `-rf64 never` that can
be enabled.
---
 libavformat/wavenc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/wavenc.c b/libavformat/wavenc.c
index a515f4e2a2..835a2157bc 100644
--- a/libavformat/wavenc.c
+++ b/libavformat/wavenc.c
@@ -487,7 +487,7 @@ static const AVOption options[] = {
     { "off",        "Do not write peak chunk.",              0,                  AV_OPT_TYPE_CONST, { .i64 = PEAK_OFF  }, 0, 0, ENC, .unit = "peak" },
     { "on",         "Append peak chunk after wav data.",     0,                  AV_OPT_TYPE_CONST, { .i64 = PEAK_ON   }, 0, 0, ENC, .unit = "peak" },
     { "only",       "Write only peak chunk, omit wav data.", 0,                  AV_OPT_TYPE_CONST, { .i64 = PEAK_ONLY }, 0, 0, ENC, .unit = "peak" },
-    { "rf64",       "Use RF64 header rather than RIFF for large files.",    OFFSET(rf64), AV_OPT_TYPE_INT,   { .i64 = RF64_NEVER  },-1, 1, ENC, .unit = "rf64" },
+    { "rf64",       "Use RF64 header rather than RIFF for large files.",    OFFSET(rf64), AV_OPT_TYPE_INT,   { .i64 = RF64_AUTO  },-1, 1, ENC, .unit = "rf64" },
     { "auto",       "Write RF64 header if file grows large enough.",        0,            AV_OPT_TYPE_CONST, { .i64 = RF64_AUTO   }, 0, 0, ENC, .unit = "rf64" },
     { "always",     "Always write RF64 header regardless of file size.",    0,            AV_OPT_TYPE_CONST, { .i64 = RF64_ALWAYS }, 0, 0, ENC, .unit = "rf64" },
     { "never",      "Never write RF64 header regardless of file size.",     0,            AV_OPT_TYPE_CONST, { .i64 = RF64_NEVER  }, 0, 0, ENC, .unit = "rf64" },
-- 
2.52.0

_______________________________________________
ffmpeg-devel mailing list -- ffmpeg-devel@ffmpeg.org
To unsubscribe send an email to ffmpeg-devel-leave@ffmpeg.org

[FFmpeg-devel] Re: [PATCH] avformat/wavenc: use RF64 when needed

[Michael Niedermayer via ffmpeg-devel]

[-- Attachment #1.1: Type: text/plain, Size: 3848 bytes --]

Hi Jason

On Sat, Dec 20, 2025 at 10:28:39PM +0100, Jason A. Donenfeld via ffmpeg-devel wrote:
> Currently if you encode a large wav, ffmpeg will hint after the fact
> that the resultant file is corrupted, because traditional wav cannot
> handle lengths greater than 32-bits. This isn't very useful; nobody
> benefits from getting garbage files.
> 
> You can manually work around this by adding `-rf64 always`, which most
> players have support for. Most people don't remember to do this until
> after the fact when their file is corrupted, or they don't figure it out
> at all and wind up using the w64 container instead.
> 
> And so that's what `-rf64 auto` is for. It uses the larger format when
> needed, and if not, uses the traditional wav that is probably more
> compatible. The result of using `-rf64 auto` is that you can add it to
> every command line -- and should add it to every command line -- to get
> either a normal small file, or a non-corrupt large file.
> 
> This is a very sensible default to have on, rather than just producing
> corrupt files and having users scrambling for solutions, and then having
> to do a potentially expensive reencode after. With `-rf64 auto` on by
> default, the user always gets a readable good file. And for users who
> sometimes want corrupt files, there still exists `-rf64 never` that can
> be enabled.
> ---
>  libavformat/wavenc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libavformat/wavenc.c b/libavformat/wavenc.c
> index a515f4e2a2..835a2157bc 100644
> --- a/libavformat/wavenc.c
> +++ b/libavformat/wavenc.c
> @@ -487,7 +487,7 @@ static const AVOption options[] = {
>      { "off",        "Do not write peak chunk.",              0,                  AV_OPT_TYPE_CONST, { .i64 = PEAK_OFF  }, 0, 0, ENC, .unit = "peak" },
>      { "on",         "Append peak chunk after wav data.",     0,                  AV_OPT_TYPE_CONST, { .i64 = PEAK_ON   }, 0, 0, ENC, .unit = "peak" },
>      { "only",       "Write only peak chunk, omit wav data.", 0,                  AV_OPT_TYPE_CONST, { .i64 = PEAK_ONLY }, 0, 0, ENC, .unit = "peak" },
> -    { "rf64",       "Use RF64 header rather than RIFF for large files.",    OFFSET(rf64), AV_OPT_TYPE_INT,   { .i64 = RF64_NEVER  },-1, 1, ENC, .unit = "rf64" },
> +    { "rf64",       "Use RF64 header rather than RIFF for large files.",    OFFSET(rf64), AV_OPT_TYPE_INT,   { .i64 = RF64_AUTO  },-1, 1, ENC, .unit = "rf64" },
>      { "auto",       "Write RF64 header if file grows large enough.",        0,            AV_OPT_TYPE_CONST, { .i64 = RF64_AUTO   }, 0, 0, ENC, .unit = "rf64" },
>      { "always",     "Always write RF64 header regardless of file size.",    0,            AV_OPT_TYPE_CONST, { .i64 = RF64_ALWAYS }, 0, 0, ENC, .unit = "rf64" },
>      { "never",      "Never write RF64 header regardless of file size.",     0,            AV_OPT_TYPE_CONST, { .i64 = RF64_NEVER  }, 0, 0, ENC, .unit = "rf64" },

breaks fate:

--- -	2025-12-21 04:04:18.901071242 +0100
+++ tests/data/fate/filter-channelmap-one-str	2025-12-21 04:04:18.898363748 +0100
@@ -1 +1 @@
-e18791f65ce5861e130b2c3e472ab90a
+8f8a664b694f18e1e9ae1b9ccfa6f30c
Test filter-channelmap-one-str failed. Look at tests/data/fate/filter-channelmap-one-str.err for details.
make: *** [tests/Makefile:323: fate-filter-channelmap-one-str] Error 1

if this change is intended, then update the fate tests and explain in the commit message
why they change

thx

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The real ebay dictionary, page 1
"Used only once"    - "Some unspecified defect prevented a second use"
"In good condition" - "Can be repaird by experienced expert"
"As is" - "You wouldnt want it even if you were payed for it, if you knew ..."

[-- Attachment #1.2: signature.asc --]
[-- Type: application/pgp-signature, Size: 195 bytes --]

[-- Attachment #2: Type: text/plain, Size: 163 bytes --]

_______________________________________________
ffmpeg-devel mailing list -- ffmpeg-devel@ffmpeg.org
To unsubscribe send an email to ffmpeg-devel-leave@ffmpeg.org