From cd1fc36be5286e8d73145fd3e026e2e9eddea540 Mon Sep 17 00:00:00 2001
From: Paul B Mahol <onemda@gmail.com>
Date: Fri, 9 Sep 2022 09:57:12 +0200
Subject: [PATCH 2/2] avcodec: add Micronas SC-4 parser

Signed-off-by: Paul B Mahol <onemda@gmail.com>
---
 libavcodec/Makefile       |  1 +
 libavcodec/misc4_parser.c | 81 +++++++++++++++++++++++++++++++++++++++
 libavcodec/parsers.c      |  1 +
 3 files changed, 83 insertions(+)
 create mode 100644 libavcodec/misc4_parser.c

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 4112a0fb2e..e938564a1f 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -1143,6 +1143,7 @@ OBJS-$(CONFIG_HEVC_PARSER)             += hevc_parser.o hevc_data.o
 OBJS-$(CONFIG_HDR_PARSER)              += hdr_parser.o
 OBJS-$(CONFIG_IPU_PARSER)              += ipu_parser.o
 OBJS-$(CONFIG_JPEG2000_PARSER)         += jpeg2000_parser.o
+OBJS-$(CONFIG_MISC4_PARSER)            += misc4_parser.o
 OBJS-$(CONFIG_MJPEG_PARSER)            += mjpeg_parser.o
 OBJS-$(CONFIG_MLP_PARSER)              += mlp_parse.o mlp_parser.o mlp.o
 OBJS-$(CONFIG_MPEG4VIDEO_PARSER)       += mpeg4video_parser.o h263.o \
diff --git a/libavcodec/misc4_parser.c b/libavcodec/misc4_parser.c
new file mode 100644
index 0000000000..d234dbb629
--- /dev/null
+++ b/libavcodec/misc4_parser.c
@@ -0,0 +1,81 @@
+/*
+ * Micronas SC-4 parser
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "parser.h"
+
+typedef struct MISC4Context {
+    ParseContext pc;
+} MISC4Context;
+
+static int misc4_parse(AVCodecParserContext *s, AVCodecContext *avctx,
+                       const uint8_t **poutbuf, int *poutbuf_size,
+                       const uint8_t *buf, int buf_size)
+{
+    MISC4Context *ctx = s->priv_data;
+    uint32_t state = ctx->pc.state;
+    int next = END_NOT_FOUND, i = 0;
+
+    *poutbuf_size = 0;
+    *poutbuf = NULL;
+
+    if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
+        next = buf_size;
+    } else {
+        uint32_t marker = 0;
+
+        switch (avctx->sample_rate) {
+        case 8000:
+        case 11025:
+            marker = 0x11b;
+            break;
+        case 16000:
+        case 32000:
+            marker = 0x2b2;
+            break;
+        }
+
+        for (; i < buf_size; i++) {
+            state = (state << 8) | buf[i];
+            if (state == marker && i > 3) {
+                next = i - 3;
+                break;
+            }
+        }
+
+        ctx->pc.state = state;
+        if (ff_combine_frame(&ctx->pc, next, &buf, &buf_size) < 0) {
+            *poutbuf = NULL;
+            *poutbuf_size = 0;
+            return buf_size;
+        }
+    }
+
+    *poutbuf      = buf;
+    *poutbuf_size = buf_size;
+
+    return next;
+}
+
+const AVCodecParser ff_misc4_parser = {
+    .codec_ids      = { AV_CODEC_ID_MISC4 },
+    .priv_data_size = sizeof(MISC4Context),
+    .parser_parse   = misc4_parse,
+    .parser_close   = ff_parse_close,
+};
diff --git a/libavcodec/parsers.c b/libavcodec/parsers.c
index a8d52af6cb..362f6f8bc6 100644
--- a/libavcodec/parsers.c
+++ b/libavcodec/parsers.c
@@ -53,6 +53,7 @@ extern const AVCodecParser ff_hevc_parser;
 extern const AVCodecParser ff_hdr_parser;
 extern const AVCodecParser ff_ipu_parser;
 extern const AVCodecParser ff_jpeg2000_parser;
+extern const AVCodecParser ff_misc4_parser;
 extern const AVCodecParser ff_mjpeg_parser;
 extern const AVCodecParser ff_mlp_parser;
 extern const AVCodecParser ff_mpeg4video_parser;
-- 
2.37.2