early-access version 1432

externals/ffmpeg/libavcodec/dca_core_bsf.c

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2016 Paul B Mahol
+ *
+ * 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 "bsf.h"
+#include "bsf_internal.h"
+#include "bytestream.h"
+#include "dca_syncwords.h"
+
+static int dca_core_filter(AVBSFContext *ctx, AVPacket *pkt)
+{
+    GetByteContext gb;
+    uint32_t syncword;
+    int core_size = 0, ret;
+
+    ret = ff_bsf_get_packet_ref(ctx, pkt);
+    if (ret < 0)
+        return ret;
+
+    bytestream2_init(&gb, pkt->data, pkt->size);
+    syncword = bytestream2_get_be32(&gb);
+    bytestream2_skip(&gb, 1);
+
+    switch (syncword) {
+    case DCA_SYNCWORD_CORE_BE:
+        core_size = ((bytestream2_get_be24(&gb) >> 4) & 0x3fff) + 1;
+        break;
+    }
+
+    if (core_size > 0 && core_size <= pkt->size) {
+        pkt->size = core_size;
+    }
+
+    return 0;
+}
+
+static const enum AVCodecID codec_ids[] = {
+    AV_CODEC_ID_DTS, AV_CODEC_ID_NONE,
+};
+
+const AVBitStreamFilter ff_dca_core_bsf = {
+    .name      = "dca_core",
+    .filter    = dca_core_filter,
+    .codec_ids = codec_ids,
+};