[FFmpeg-devel] [PATCH] avcodec/libopusenc: Fix for header pre-skip value

Arthur Taylor art at ified.ca
Thu Jan 7 22:55:59 EET 2021


The Opus header initial padding preskip amount is always to be expressed
relative to 48kHz. However, the encoder delay returned from querying
libopus is relative to the encoding samplerate. Multiply by the
samplerate conversion factor to correct.

Signed-off-by: Arthur Taylor <art at ified.ca>
---
 libavcodec/libopusenc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/libopusenc.c b/libavcodec/libopusenc.c
index bf2d04b4fb..70d17f802b 100644
--- a/libavcodec/libopusenc.c
+++ b/libavcodec/libopusenc.c
@@ -94,7 +94,7 @@ static void libopus_write_header(AVCodecContext *avctx, int stream_count,
     bytestream_put_buffer(&p, "OpusHead", 8);
     bytestream_put_byte(&p, 1); /* Version */
     bytestream_put_byte(&p, channels);
-    bytestream_put_le16(&p, avctx->initial_padding); /* Lookahead samples at 48kHz */
+    bytestream_put_le16(&p, avctx->initial_padding * 48000 / avctx->sample_rate); /* Lookahead samples at 48kHz */
     bytestream_put_le32(&p, avctx->sample_rate); /* Original sample rate */
     bytestream_put_le16(&p, 0); /* Gain of 0dB is recommended. */
 
-- 
2.30.0



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