vp8: Return stream format information from parser

libavcodec/vp8_parser.c

 /*
- * Copyright (C) 2008 Michael Niedermayer
- *
  * This file is part of Libav.
  *
  * Libav is free software; you can redistribute it and/or
@@ -18,15 +16,56 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#include "parser.h"
+#include "libavutil/intreadwrite.h"
+
+#include "avcodec.h"
 
 static int parse(AVCodecParserContext *s,
                  AVCodecContext *avctx,
                  const uint8_t **poutbuf, int *poutbuf_size,
                  const uint8_t *buf, int buf_size)
 {
-    s->pict_type = (buf[0] & 0x01) ? AV_PICTURE_TYPE_P
-                                   : AV_PICTURE_TYPE_I;
+    unsigned int frame_type;
+    unsigned int profile;
+
+    if (buf_size < 3)
+        return AVERROR_INVALIDDATA;
+
+    frame_type = buf[0] & 1;
+    profile    = (buf[0] >> 1) & 7;
+    if (profile > 3) {
+        av_log(avctx, AV_LOG_ERROR, "Invalid profile %u.\n", profile);
+        return AVERROR_INVALIDDATA;
+    }
+
+    avctx->profile = profile;
+    s->key_frame   = frame_type == 0;
+    s->pict_type   = frame_type ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
+    s->format      = AV_PIX_FMT_YUV420P;
+    s->field_order = AV_FIELD_PROGRESSIVE;
+    s->picture_structure = AV_PICTURE_STRUCTURE_FRAME;
+
+    if (frame_type == 0) {
+        unsigned int sync_code;
+        unsigned int width, height;
+
+        if (buf_size < 10)
+            return AVERROR_INVALIDDATA;
+
+        sync_code = AV_RL24(buf + 3);
+        if (sync_code != 0x2a019d) {
+            av_log(avctx, AV_LOG_ERROR, "Invalid sync code %06x.\n", sync_code);
+            return AVERROR_INVALIDDATA;
+        }
+
+        width  = AV_RL16(buf + 6) & 0x3fff;
+        height = AV_RL16(buf + 8) & 0x3fff;
+
+        s->width        = width;
+        s->height       = height;
+        s->coded_width  = FFALIGN(width,  16);
+        s->coded_height = FFALIGN(height, 16);
+    }
 
     *poutbuf      = buf;
     *poutbuf_size = buf_size;