| Message ID | 508e4a66.c25fb40a.02b1.ffffbb4e@mx.google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Javier, Am Montag, den 29.10.2012, 10:20 +0100 schrieb javier.martin@vista-silicon.com: > From: Javier Martin <javier.martin@vista-silicon.com> > > Length of H.264 headers is variable and thus it might not be > aligned for the coda to append the encoded frame. This causes > the first frame to overwrite part of the H.264 PPS. > > In order to solve that, a filler NAL must be added between > the headers and the first frame to preserve alignment. I can reproduce this, but CODA7/9 even need 64-bit alignment. > Signed-off-by: Javier Martin <javier.martin@vista-silicon.com> > --- > drivers/media/platform/coda.c | 33 ++++++++++++++++++++++++++++++++- > 1 file changed, 32 insertions(+), 1 deletion(-) > > diff --git a/drivers/media/platform/coda.c b/drivers/media/platform/coda.c > index a8c7a94..4cdb4f4 100644 > --- a/drivers/media/platform/coda.c > +++ b/drivers/media/platform/coda.c > @@ -177,6 +177,8 @@ struct coda_ctx { > int idx; > }; > > +static u8 coda_filler_nal[] = { 0x00, 0x00, 0x00, 0x01, 0x0c, 0xff, 0xff, 0xff, 0xff, 0xff}; > + > static inline void coda_write(struct coda_dev *dev, u32 data, u32 reg) > { > v4l2_dbg(1, coda_debug, &dev->v4l2_dev, > @@ -938,6 +940,29 @@ static int coda_alloc_framebuffers(struct coda_ctx *ctx, struct coda_q_data *q_d > return 0; > } > > +static int coda_h264_padding(int size, char *p) > +{ > + int size_align = size & ~0x3; > + int filler_size = ARRAY_SIZE(coda_filler_nal); > + int nal_size; > + int diff; > + > + diff = size - size_align; > + if (diff == 0) > + return 0; > + > + nal_size = filler_size + 2 - diff; > + if (nal_size > filler_size) > + nal_size -= 4; > + > + memcpy(p, coda_filler_nal, nal_size); > + > + /* Add rbsp stop bit and trailing at the end */ > + *(p + nal_size - 1) = 0x80; > + > + return nal_size; > +} > + > static int coda_start_streaming(struct vb2_queue *q, unsigned int count) > { > struct coda_ctx *ctx = vb2_get_drv_priv(q); > @@ -1165,7 +1190,13 @@ static int coda_start_streaming(struct vb2_queue *q, unsigned int count) > coda_read(dev, CODA_CMD_ENC_HEADER_BB_START); > memcpy(&ctx->vpu_header[1][0], vb2_plane_vaddr(buf, 0), > ctx->vpu_header_size[1]); > - ctx->vpu_header_size[2] = 0; > + /* > + * Length of H.264 headers is variable and thus it might not be > + * aligned for the coda to append the encoded frame. In that is > + * the case a filler NAL must be added to header 2. > + */ > + ctx->vpu_header_size[2] = coda_h264_padding((ctx->vpu_header_size[0] + > + ctx->vpu_header_size[1]), ctx->vpu_header[2]); > break; > case V4L2_PIX_FMT_MPEG4: > /* regards Philipp -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/media/platform/coda.c b/drivers/media/platform/coda.c index a8c7a94..4cdb4f4 100644 --- a/drivers/media/platform/coda.c +++ b/drivers/media/platform/coda.c @@ -177,6 +177,8 @@ struct coda_ctx { int idx; }; +static u8 coda_filler_nal[] = { 0x00, 0x00, 0x00, 0x01, 0x0c, 0xff, 0xff, 0xff, 0xff, 0xff}; + static inline void coda_write(struct coda_dev *dev, u32 data, u32 reg) { v4l2_dbg(1, coda_debug, &dev->v4l2_dev, @@ -938,6 +940,29 @@ static int coda_alloc_framebuffers(struct coda_ctx *ctx, struct coda_q_data *q_d return 0; } +static int coda_h264_padding(int size, char *p) +{ + int size_align = size & ~0x3; + int filler_size = ARRAY_SIZE(coda_filler_nal); + int nal_size; + int diff; + + diff = size - size_align; + if (diff == 0) + return 0; + + nal_size = filler_size + 2 - diff; + if (nal_size > filler_size) + nal_size -= 4; + + memcpy(p, coda_filler_nal, nal_size); + + /* Add rbsp stop bit and trailing at the end */ + *(p + nal_size - 1) = 0x80; + + return nal_size; +} + static int coda_start_streaming(struct vb2_queue *q, unsigned int count) { struct coda_ctx *ctx = vb2_get_drv_priv(q); @@ -1165,7 +1190,13 @@ static int coda_start_streaming(struct vb2_queue *q, unsigned int count) coda_read(dev, CODA_CMD_ENC_HEADER_BB_START); memcpy(&ctx->vpu_header[1][0], vb2_plane_vaddr(buf, 0), ctx->vpu_header_size[1]); - ctx->vpu_header_size[2] = 0; + /* + * Length of H.264 headers is variable and thus it might not be + * aligned for the coda to append the encoded frame. In that is + * the case a filler NAL must be added to header 2. + */ + ctx->vpu_header_size[2] = coda_h264_padding((ctx->vpu_header_size[0] + + ctx->vpu_header_size[1]), ctx->vpu_header[2]); break; case V4L2_PIX_FMT_MPEG4: /*