avcodec: add Micronas SC-4 parser

1 files changed, 81 insertions, 0 deletions

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,
+};