From d180aebb6bee4efdced23dd3fb46cadd69da426a Mon Sep 17 00:00:00 2001
From: Yandong Lin <yandong.lin@rock-chips.com>
Date: Wed, 12 Jul 2023 15:03:52 +0800
Subject: [PATCH] [mpp_bitread]: add new type for sei payload parse

The quantity of emulation prevention bytes is not
included in the size payloadSize of an SEI payload.
So add PSEUDO_CODE_H264_H265_SEI type for sei payload parse.

Signed-off-by: Yandong Lin <yandong.lin@rock-chips.com>
Change-Id: I92554de98ffca2f81785aa81b2f652099dbe6ae9
---
 mpp/base/inc/mpp_bitread.h |  1 +
 mpp/base/mpp_bitread.c     | 26 ++++++++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/mpp/base/inc/mpp_bitread.h b/mpp/base/inc/mpp_bitread.h
index 538e21f3..ead014e1 100644
--- a/mpp/base/inc/mpp_bitread.h
+++ b/mpp/base/inc/mpp_bitread.h
@@ -96,6 +96,7 @@
 typedef enum  PseudoCodeType_e {
     PSEUDO_CODE_NONE = 0,
     PSEUDO_CODE_H264_H265,
+    PSEUDO_CODE_H264_H265_SEI,
     PSEUDO_CODE_AVS2,
     PSEUDO_CODE_BUT
 } PseudoCodeType;
diff --git a/mpp/base/mpp_bitread.c b/mpp/base/mpp_bitread.c
index afda2922..e5ec1f8e 100644
--- a/mpp/base/mpp_bitread.c
+++ b/mpp/base/mpp_bitread.c
@@ -63,6 +63,29 @@ static MPP_RET update_curbyte_h264(BitReadCtx_t *bitctx)
     return MPP_OK;
 }
 
+static MPP_RET update_curbyte_h2645_sei(BitReadCtx_t *bitctx)
+{
+    if (bitctx->bytes_left_ < 1)
+        return  MPP_ERR_READ_BIT;
+
+    // Emulation prevention three-byte detection.
+    // If a sequence of 0x000003 is found, skip (ignore) the last byte (0x03).
+    if ((*bitctx->data_ == 0x03)
+        && ((bitctx->prev_two_bytes_ & 0xffff) == 0)) {
+        // Detected 0x000003, skip last byte.
+        ++bitctx->data_;
+        // Need another full three bytes before we can detect the sequence again.
+        bitctx->prev_two_bytes_ = 0xffff;
+    }
+    // Load a new byte and advance pointers.
+    bitctx->curr_byte_ = *bitctx->data_++ & 0xff;
+    --bitctx->bytes_left_;
+    bitctx->num_remaining_bits_in_curr_byte_ = 8;
+    bitctx->prev_two_bytes_ = (bitctx->prev_two_bytes_ << 8) | bitctx->curr_byte_;
+
+    return MPP_OK;
+}
+
 static MPP_RET update_curbyte_avs2(BitReadCtx_t *bitctx)
 {
     if (bitctx->bytes_left_ < 1)
@@ -320,6 +343,9 @@ void mpp_set_bitread_pseudo_code_type(BitReadCtx_t *bitctx, PseudoCodeType type)
     case PSEUDO_CODE_H264_H265:
         bitctx->update_curbyte = update_curbyte_h264;
         break;
+    case PSEUDO_CODE_H264_H265_SEI:
+        bitctx->update_curbyte = update_curbyte_h2645_sei;
+        break;
     case PSEUDO_CODE_AVS2:
         bitctx->update_curbyte = update_curbyte_avs2;
         break;