avcodec/hevcdec: remove HEVCContext usage from ff_hevc_compute_poc()

Move it to hevc_ps as well. This is in preparation for a following patch.

Reviewed-by: Hendrik Leppkes <h.leppkes@gmail.com>
Reviewed-by: Aaron Levinson <alevinsn@aracnet.com>
Signed-off-by: James Almer <jamrial@gmail.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/libavcodec/hevc_ps.c b/libavcodec/hevc_ps.c
index 6d67dd9c69..b5a970e4f7 100644
--- a/libavcodec/hevc_ps.c
+++ b/libavcodec/hevc_ps.c
@@ -1665,3 +1665,26 @@ err:
     av_buffer_unref(&pps_buf);
     return ret;
 }
+
+int ff_hevc_compute_poc(const HEVCSPS *sps, int pocTid0, int poc_lsb, int nal_unit_type)
+{
+    int max_poc_lsb  = 1 << sps->log2_max_poc_lsb;
+    int prev_poc_lsb = pocTid0 % max_poc_lsb;
+    int prev_poc_msb = pocTid0 - prev_poc_lsb;
+    int poc_msb;
+
+    if (poc_lsb < prev_poc_lsb && prev_poc_lsb - poc_lsb >= max_poc_lsb / 2)
+        poc_msb = prev_poc_msb + max_poc_lsb;
+    else if (poc_lsb > prev_poc_lsb && poc_lsb - prev_poc_lsb > max_poc_lsb / 2)
+        poc_msb = prev_poc_msb - max_poc_lsb;
+    else
+        poc_msb = prev_poc_msb;
+
+    // For BLA picture types, POCmsb is set to 0.
+    if (nal_unit_type == HEVC_NAL_BLA_W_LP   ||
+        nal_unit_type == HEVC_NAL_BLA_W_RADL ||
+        nal_unit_type == HEVC_NAL_BLA_N_LP)
+        poc_msb = 0;
+
+    return poc_msb + poc_lsb;
+}