Commit cd5cea20 authored by Boris Brezillon's avatar Boris Brezillon Committed by Ezequiel Garcia

media: hantro: h264: Fix the frame_num wraparound case

Step ' Decoding process for picture numbers' was missing in the
reflist creation logic, leading to invalid P reflists when a
->frame_num wraparound happens.

Fixes: a9471e25 ("media: hantro: Add core bits to support H264 decoding")
Reported-by: default avatarFrancois Buergisser <>
Signed-off-by: Boris Brezillon's avatarBoris Brezillon <>
Reviewed-by: default avatarPhilipp Zabel <>
Tested-by: default avatarPhilipp Zabel <>
Tested-by: default avatarFrancois Buergisser <>
Reviewed-by: default avatarTomasz Figa <>
Signed-off-by: default avatarHans Verkuil <>
Signed-off-by: default avatarMauro Carvalho Chehab <>
parent 985c6ade
......@@ -271,6 +271,7 @@ struct hantro_h264_reflist_builder {
const struct v4l2_h264_dpb_entry *dpb;
s32 pocs[HANTRO_H264_DPB_SIZE];
u8 unordered_reflist[HANTRO_H264_DPB_SIZE];
int frame_nums[HANTRO_H264_DPB_SIZE];
s32 curpoc;
u8 num_valid;
......@@ -294,13 +295,20 @@ static void
init_reflist_builder(struct hantro_ctx *ctx,
struct hantro_h264_reflist_builder *b)
const struct v4l2_ctrl_h264_slice_params *slice_params;
const struct v4l2_ctrl_h264_decode_params *dec_param;
const struct v4l2_ctrl_h264_sps *sps;
struct vb2_v4l2_buffer *buf = hantro_get_dst_buf(ctx);
const struct v4l2_h264_dpb_entry *dpb = ctx->h264_dec.dpb;
struct vb2_queue *cap_q = &ctx->fh.m2m_ctx->cap_q_ctx.q;
int cur_frame_num, max_frame_num;
unsigned int i;
dec_param = ctx->h264_dec.ctrls.decode;
slice_params = &ctx->h264_dec.ctrls.slices[0];
sps = ctx->h264_dec.ctrls.sps;
max_frame_num = 1 << (sps->log2_max_frame_num_minus4 + 4);
cur_frame_num = slice_params->frame_num;
memset(b, 0, sizeof(*b));
b->dpb = dpb;
......@@ -318,6 +326,18 @@ init_reflist_builder(struct hantro_ctx *ctx,
buf = to_vb2_v4l2_buffer(vb2_get_buffer(cap_q, buf_idx));
* Handle frame_num wraparound as described in section
* ' Decoding process for picture numbers' of the spec.
* TODO: This logic will have to be adjusted when we start
* supporting interlaced content.
if (dpb[i].frame_num > cur_frame_num)
b->frame_nums[i] = (int)dpb[i].frame_num - max_frame_num;
b->frame_nums[i] = dpb[i].frame_num;
b->pocs[i] = get_poc(buf->field, dpb[i].top_field_order_cnt,
b->unordered_reflist[b->num_valid] = i;
......@@ -353,7 +373,8 @@ static int p_ref_list_cmp(const void *ptra, const void *ptrb, const void *data)
* ascending order.
if (!(a->flags & V4L2_H264_DPB_ENTRY_FLAG_LONG_TERM))
return HANTRO_CMP(b->frame_num, a->frame_num);
return HANTRO_CMP(builder->frame_nums[idxb],
return HANTRO_CMP(a->pic_num, b->pic_num);
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