DPX parser

Additional improvements and fixes by Michael Niedermayer <michaelni@gmx.at>.

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

1 files changed, 116 insertions, 0 deletions

diff --git a/libavcodec/dpx_parser.c b/libavcodec/dpx_parser.c
new file mode 100644
index 0000000000..e3a7ac5c35
--- /dev/null
+++ b/libavcodec/dpx_parser.c
@@ -0,0 +1,116 @@
+/*
+ * DPX parser
+ * Copyright (c) 2013 Paul B Mahol
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * DPX parser
+ */
+
+#include "libavutil/bswap.h"
+#include "libavutil/common.h"
+
+#include "parser.h"
+
+typedef struct DPXParseContext {
+    ParseContext pc;
+    uint32_t index;
+    uint32_t fsize;
+    uint32_t remaining_size;
+    int is_be;
+} DPXParseContext;
+
+static int dpx_parse(AVCodecParserContext *s, AVCodecContext *avctx,
+                     const uint8_t **poutbuf, int *poutbuf_size,
+                     const uint8_t *buf, int buf_size)
+{
+    DPXParseContext *d = s->priv_data;
+    uint32_t state = d->pc.state;
+    int next = END_NOT_FOUND;
+    int i = 0;
+
+    s->pict_type = AV_PICTURE_TYPE_I;
+
+    *poutbuf_size = 0;
+    if (buf_size == 0)
+        next = 0;
+
+    if (!d->pc.frame_start_found) {
+        for (; i < buf_size; i++) {
+            state = (state << 8) | buf[i];
+            if (state == MKBETAG('S','D','P','X') ||
+                state == MKTAG('S','D','P','X')) {
+                d->pc.frame_start_found = 1;
+                d->is_be = state == MKBETAG('S','D','P','X');
+                d->index = 0;
+                break;
+            }
+        }
+        d->pc.state = state;
+    } else {
+        if (d->remaining_size) {
+            i = FFMIN(d->remaining_size, buf_size);
+            d->remaining_size -= i;
+            if (d->remaining_size)
+                goto flush;
+        }
+    }
+
+    for (; d->pc.frame_start_found && i < buf_size; i++) {
+        d->pc.state = (d->pc.state << 8) | buf[i];
+        d->index++;
+        if (d->index == 17) {
+            d->fsize = d->is_be ? d->pc.state : av_bswap32(d->pc.state);
+            if (d->fsize <= 1664) {
+                d->pc.frame_start_found = 0;
+                goto flush;
+            }
+            if (d->fsize > buf_size - i + 19)
+                d->remaining_size = d->fsize - buf_size + i - 19;
+            else
+                i += d->fsize - 19;
+
+            break;
+        } else if (d->index > 17) {
+            if (d->pc.state == MKBETAG('S','D','P','X') ||
+                d->pc.state == MKTAG('S','D','P','X')) {
+                next = i - 3;
+                break;
+            }
+        }
+    }
+
+flush:
+    if (ff_combine_frame(&d->pc, next, &buf, &buf_size) < 0)
+        return buf_size;
+
+    d->pc.frame_start_found = 0;
+
+    *poutbuf      = buf;
+    *poutbuf_size = buf_size;
+    return next;
+}
+
+AVCodecParser ff_dpx_parser = {
+    .codec_ids      = { AV_CODEC_ID_DPX },
+    .priv_data_size = sizeof(DPXParseContext),
+    .parser_parse   = dpx_parse,
+    .parser_close   = ff_parse_close,
+};