[media] coda: pad first h.264 buffer to 512 bytes

The bitstream reader needs 512 bytes ready to read to examine the
headers in the first frame. If that frame is too small, prepend it
with a filler NAL.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

diff --git a/drivers/media/platform/coda/coda-bit.c b/drivers/media/platform/coda/coda-bit.c
index e3e32256078367e72b6e467f83e0dcbb65ca8c09..89965ca5bd250c444b0844e2f734dec741b25b3d 100644 (file)
--- a/drivers/media/platform/coda/coda-bit.c
+++ b/drivers/media/platform/coda/coda-bit.c
@@ -179,6 +179,25 @@ static void coda_kfifo_sync_to_device_write(struct coda_ctx *ctx)
        coda_write(dev, wr_ptr, CODA_REG_BIT_WR_PTR(ctx->reg_idx));
 }
 
+static int coda_bitstream_pad(struct coda_ctx *ctx, u32 size)
+{
+       unsigned char *buf;
+       u32 n;
+
+       if (size < 6)
+               size = 6;
+
+       buf = kmalloc(size, GFP_KERNEL);
+       if (!buf)
+               return -ENOMEM;
+
+       coda_h264_filler_nal(size, buf);
+       n = kfifo_in(&ctx->bitstream_fifo, buf, size);
+       kfree(buf);
+
+       return (n < size) ? -ENOSPC : 0;
+}
+
 static int coda_bitstream_queue(struct coda_ctx *ctx,
                                struct vb2_v4l2_buffer *src_buf)
 {
@@ -198,10 +217,10 @@ static int coda_bitstream_queue(struct coda_ctx *ctx,
 static bool coda_bitstream_try_queue(struct coda_ctx *ctx,
                                     struct vb2_v4l2_buffer *src_buf)
 {
+       unsigned long payload = vb2_get_plane_payload(&src_buf->vb2_buf, 0);
        int ret;
 
-       if (coda_get_bitstream_payload(ctx) +
-           vb2_get_plane_payload(&src_buf->vb2_buf, 0) + 512 >=
+       if (coda_get_bitstream_payload(ctx) + payload + 512 >=
            ctx->bitstream.size)
                return false;
 
@@ -210,6 +229,11 @@ static bool coda_bitstream_try_queue(struct coda_ctx *ctx,
                return true;
        }
 
+       /* Add zero padding before the first H.264 buffer, if it is too small */
+       if (ctx->qsequence == 0 && payload < 512 &&
+           ctx->codec->src_fourcc == V4L2_PIX_FMT_H264)
+               coda_bitstream_pad(ctx, 512 - payload);
+
        ret = coda_bitstream_queue(ctx, src_buf);
        if (ret < 0) {
                v4l2_err(&ctx->dev->v4l2_dev, "bitstream buffer overflow\n");

diff --git a/drivers/media/platform/coda/coda-h264.c b/drivers/media/platform/coda/coda-h264.c
index 09dfcca7cc500f5f4784409cdd1b1b0c962efb82..dc137c3fd510bbaa5ae789568e155e988373c4e2 100644 (file)
--- a/drivers/media/platform/coda/coda-h264.c
+++ b/drivers/media/platform/coda/coda-h264.c
@@ -15,10 +15,25 @@
 #include <linux/string.h>
 #include <coda.h>
 
-static const u8 coda_filler_nal[14] = { 0x00, 0x00, 0x00, 0x01, 0x0c, 0xff,
-                       0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x80 };
 static const u8 coda_filler_size[8] = { 0, 7, 14, 13, 12, 11, 10, 9 };
 
+int coda_h264_filler_nal(int size, char *p)
+{
+       if (size < 6)
+               return -EINVAL;
+
+       p[0] = 0x00;
+       p[1] = 0x00;
+       p[2] = 0x00;
+       p[3] = 0x01;
+       p[4] = 0x0c;
+       memset(p + 5, 0xff, size - 6);
+       /* Add rbsp stop bit and trailing at the end */
+       p[size - 1] = 0x80;
+
+       return 0;
+}
+
 int coda_h264_padding(int size, char *p)
 {
        int nal_size;
@@ -29,10 +44,7 @@ int coda_h264_padding(int size, char *p)
                return 0;
 
        nal_size = coda_filler_size[diff];
-       memcpy(p, coda_filler_nal, nal_size);
-
-       /* Add rbsp stop bit and trailing at the end */
-       *(p + nal_size - 1) = 0x80;
+       coda_h264_filler_nal(nal_size, p);
 
        return nal_size;
 }

diff --git a/drivers/media/platform/coda/coda.h b/drivers/media/platform/coda/coda.h
index 6aa9c19c4a896fa973cad4c3dc33c7878582d176..a730bc2a2ff99538d4e46fc407b4519f9c41835a 100644 (file)
--- a/drivers/media/platform/coda/coda.h
+++ b/drivers/media/platform/coda/coda.h
@@ -290,6 +290,7 @@ void coda_bit_stream_end_flag(struct coda_ctx *ctx);
 void coda_m2m_buf_done(struct coda_ctx *ctx, struct vb2_v4l2_buffer *buf,
                       enum vb2_buffer_state state);
 
+int coda_h264_filler_nal(int size, char *p);
 int coda_h264_padding(int size, char *p);
 
 bool coda_jpeg_check_buffer(struct coda_ctx *ctx, struct vb2_buffer *vb);