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 ..."