With bitstream padding, it is possible to decode a single JPEG in the bitstream
immediately. This allows us to only ever queue a single JPEG into the bitstream
buffer, except to increase payload over 512 bytes or to back out of hold state.
This is a measure to decrease JPEG decoder latency.
Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
---
drivers/media/platform/coda/coda-bit.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/media/platform/coda/coda-bit.c b/drivers/media/platform/coda/coda-bit.c
index 27e0764..2a6810e 100644
--- a/drivers/media/platform/coda/coda-bit.c
+++ b/drivers/media/platform/coda/coda-bit.c
@@ -221,6 +221,14 @@ void coda_fill_bitstream(struct coda_ctx *ctx)
u32 start;
while (v4l2_m2m_num_src_bufs_ready(ctx->fh.m2m_ctx) > 0) {
+ /*
+ * Only queue a single JPEG into the bitstream buffer, except
+ * to increase payload over 512 bytes or if in hold state.
+ */
+ if (ctx->codec->src_fourcc == V4L2_PIX_FMT_JPEG &&
+ (coda_get_bitstream_payload(ctx) >= 512) && !ctx->hold)
+ break;
+
src_buf = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
/* Buffer start position */
--
2.1.0
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