openexrdec: Instead of trying to parse the bitstream, just look for the next header

This should be more robust and allows us to handle new versions of the
file format if the library supports it.

diff --git a/ext/openexr/gstopenexrdec.cpp b/ext/openexr/gstopenexrdec.cpp
index b14cbd2..54b5f59 100644 (file)
--- a/ext/openexr/gstopenexrdec.cpp
+++ b/ext/openexr/gstopenexrdec.cpp
@@ -189,29 +189,10 @@ static GstFlowReturn
 gst_openexr_dec_parse (GstVideoDecoder * decoder,
     GstVideoCodecFrame * frame, GstAdapter * adapter, gboolean at_eos)
 {
-  GstByteReader reader;
-  const guint8 *data;
+  guint8 data[8];
   gsize size;
-  guint32 u32;
-  guint64 u64;
-  guint8 version;
-  gboolean single_tile, long_name;
-  gboolean non_image, multipart;
-  /* *INDENT-OFF * */
-  struct
-  {
-    guint32 x1, y1, x2, y2;
-  } data_window = {
-  (guint32) - 1, (guint32) - 1, (guint32) - 1, (guint32) - 1};
-  struct
-  {
-    guint32 w, h;
-    guint8 mode;
-  } tile_desc = {
-  (guint32) - 1, (guint32) - 1, (guint8) - 1};
-  guint8 compression = (guint8) - 1;
-  guint32 chunk_count = (guint32) - 1;
-  /* *INDENT-ON * */
+  guint32 magic, flags;
+  gssize offset;
 
   size = gst_adapter_available (adapter);
 
@@ -221,216 +202,43 @@ gst_openexr_dec_parse (GstVideoDecoder * decoder,
   if (size < 8)
     goto need_more_data;
 
-  data = (const guint8 *) gst_adapter_map (adapter, size);
-
-  gst_byte_reader_init (&reader, data, size);
-
-  /* Must start with the OpenEXR magic number */
-  if (!gst_byte_reader_peek_uint32_le (&reader, &u32))
-    goto need_more_data;
-
-  if (u32 != 0x01312f76) {
-    for (;;) {
-      guint offset;
-
-      offset = gst_byte_reader_masked_scan_uint32 (&reader, 0xffffffff,
-          0x762f3101, 0, gst_byte_reader_get_remaining (&reader));
-
-      if (offset == (guint) - 1) {
-        gst_adapter_flush (adapter,
-            gst_byte_reader_get_remaining (&reader) - 4);
-        goto need_more_data;
-      }
-
-      if (!gst_byte_reader_skip (&reader, offset))
-        goto need_more_data;
-
-      if (!gst_byte_reader_peek_uint32_le (&reader, &u32))
-        goto need_more_data;
+  gst_adapter_copy (adapter, data, 0, 8);
 
-      if (u32 == 0x01312f76) {
-        /* We're skipping, go out, we'll be back */
-        gst_adapter_flush (adapter, gst_byte_reader_get_pos (&reader));
-        goto need_more_data;
-      }
-      if (!gst_byte_reader_skip (&reader, 4))
-        goto need_more_data;
+  magic = GST_READ_UINT32_LE (data);
+  flags = GST_READ_UINT32_LE (data + 4);
+  if (magic != 0x01312f76 || ((flags & 0xff) != 1 && (flags & 0xff) != 2) || ((flags & 0x200) && (flags & 0x1800))) {
+    offset = gst_adapter_masked_scan_uint32_peek (adapter, 0xffffffff, 0x762f3101, 0, size, NULL);
+    if (offset == -1) {
+      gst_adapter_flush (adapter, size - 4);
+      goto need_more_data;
     }
-  }
 
-  /* Now we're at the magic number */
-  if (!gst_byte_reader_skip (&reader, 4))
+    /* come back into this function after flushing some data */
+    gst_adapter_flush (adapter, offset);
     goto need_more_data;
-
-  /* version and flags */
-  if (!gst_byte_reader_get_uint32_le (&reader, &u32))
-    goto need_more_data;
-
-  version = (u32 & 0xff);
-  if (version != 1 && version != 2) {
-    GST_ERROR_OBJECT (decoder, "Unsupported OpenEXR version %d", version);
-    return GST_FLOW_NOT_NEGOTIATED;
-  }
-  single_tile = ! !(u32 & 0x200);
-  long_name = ! !(u32 & 0x400);
-  non_image = ! !(u32 & 0x800);
-  multipart = ! !(u32 & 0x1000);
-  GST_DEBUG_OBJECT (decoder,
-      "OpenEXR image version %d, single tile %d, long name %d, non-image %d, multipart %d",
-      version, single_tile, long_name, non_image, multipart);
-
-  /* attributes */
-  if (multipart) {
-    GST_WARNING_OBJECT (decoder, "Multipart files not supported");
-    return GST_FLOW_NOT_NEGOTIATED;
-  }
-  if (non_image) {
-    GST_WARNING_OBJECT (decoder, "Deep-data images not supported");
-    return GST_FLOW_NOT_NEGOTIATED;
   }
 
-  /* Read attributes */
-  for (;;) {
-    const gchar *name, *type;
-    guint8 u8;
+  /* valid header, now let's try to find the next one unless we're EOS */
+  if (!at_eos) {
+    gboolean found = FALSE;
 
-    if (!gst_byte_reader_peek_uint8 (&reader, &u8))
-      goto need_more_data;
-    if (u8 == 0) {
-      gst_byte_reader_skip (&reader, 1);
-      break;
-    }
-
-    if (!gst_byte_reader_get_string_utf8 (&reader, &name))
-      goto need_more_data;
-    if (!gst_byte_reader_get_string_utf8 (&reader, &type))
-      goto need_more_data;
-    if (!gst_byte_reader_get_uint32_le (&reader, &u32))
-      goto need_more_data;
-    if (gst_byte_reader_get_remaining (&reader) < u32)
-      goto need_more_data;
-
-    if (strcmp (name, "dataWindow") == 0) {
-      if (strcmp (type, "box2i") != 0 || u32 != 16)
-        return GST_FLOW_ERROR;
-
-      data_window.x1 = gst_byte_reader_get_uint32_le_unchecked (&reader);
-      data_window.y1 = gst_byte_reader_get_uint32_le_unchecked (&reader);
-      data_window.x2 = gst_byte_reader_get_uint32_le_unchecked (&reader);
-      data_window.y2 = gst_byte_reader_get_uint32_le_unchecked (&reader);
-    } else if (strcmp (name, "tiles") == 0) {
-      if (strcmp (type, "tiledesc") != 0 || u32 != 9)
-        return GST_FLOW_ERROR;
-      tile_desc.w = gst_byte_reader_get_uint32_le_unchecked (&reader);
-      tile_desc.h = gst_byte_reader_get_uint32_le_unchecked (&reader);
-      tile_desc.mode = gst_byte_reader_get_uint8_unchecked (&reader);
-    } else if (strcmp (name, "compression") == 0) {
-      if (strcmp (type, "compression") != 0 || u32 != 1)
-        return GST_FLOW_ERROR;
-      compression = gst_byte_reader_get_uint8_unchecked (&reader);
-    } else if (strcmp (name, "chunkCount") == 0) {
-      if (strcmp (type, "int") != 0 || u32 != 4)
-        return GST_FLOW_ERROR;
-      chunk_count = gst_byte_reader_get_uint32_le_unchecked (&reader);
-    } else {
-      gst_byte_reader_skip_unchecked (&reader, u32);
-    }
-  }
-
-  if (data_window.x1 == (guint32) - 1)
-    return GST_FLOW_ERROR;
-  if (data_window.x2 < data_window.x1)
-    return GST_FLOW_ERROR;
-  if (data_window.y2 < data_window.y1)
-    return GST_FLOW_ERROR;
-  if (compression == (guint8) - 1)
-    return GST_FLOW_ERROR;
-  if (single_tile && tile_desc.w == (guint32) - 1)
-    return GST_FLOW_ERROR;
+    while (!found) {
+      offset = gst_adapter_masked_scan_uint32_peek (adapter, 0xffffffff, 0x762f3101, 8, size - 8 - 4, NULL);
+      if (offset == -1)
+        goto need_more_data;
 
-  GST_DEBUG_OBJECT (decoder, "Have data window (%u, %u)x(%u, %u)",
-      data_window.x1, data_window.y1, data_window.x2, data_window.y2);
-  GST_DEBUG_OBJECT (decoder, "Have compression %u", compression);
-  if (single_tile)
-    GST_DEBUG_OBJECT (decoder, "Have tiles (%u, %u), mode %u", tile_desc.w,
-        tile_desc.h, tile_desc.mode);
-
-  /* offset table */
-  if (chunk_count == (guint32) - 1) {
-    if (single_tile) {
-      guint xt, yt;
-
-      xt = data_window.x2 - data_window.x1 + 1;
-      xt = (xt + tile_desc.w - 1) / tile_desc.w;
-
-      yt = data_window.y2 - data_window.y1 + 1;
-      yt = (yt + tile_desc.h - 1) / tile_desc.h;
-
-      chunk_count = xt * yt;
-      GST_DEBUG_OBJECT (decoder, "Have %ux%u tiles", xt, yt);
-    } else {
-      chunk_count = data_window.y2 - data_window.y1 + 1;
-
-      switch (compression) {
-        case 0:                /* NO */
-        case 1:                /* RLE */
-        case 2:                /* ZIPS */
-          break;
-        case 3:                /* ZIP */
-        case 5:                /* PXR24 */
-          chunk_count = (chunk_count + 15) / 16;
-          break;
-        case 4:                /* PIZ */
-        case 6:                /* B44 */
-        case 7:                /* B44A */
-          chunk_count = (chunk_count + 31) / 32;
-          break;
-        default:
-          GST_WARNING_OBJECT (decoder, "Unsupported compression %u",
-              compression);
-          return GST_FLOW_NOT_NEGOTIATED;
-      }
+      gst_adapter_copy (adapter, data, offset, 8);
+      magic = GST_READ_UINT32_LE (data);
+      flags = GST_READ_UINT32_LE (data + 4);
+      if (magic == 0x01312f76 && ((flags & 0xff) == 1 || (flags & 0xff) == 2) && (!(flags & 0x200) || !(flags & 0x1800)))
+        found = TRUE;
     }
-  } else {
-    GST_WARNING_OBJECT (decoder, "Chunk data not supported");
-    return GST_FLOW_NOT_NEGOTIATED;
-  }
-
-  if (gst_byte_reader_get_remaining (&reader) < chunk_count * 8)
-    goto need_more_data;
-
-  gst_byte_reader_skip_unchecked (&reader, (chunk_count - 1) * 8);
-  u64 = gst_byte_reader_get_uint64_le_unchecked (&reader);
-
-  GST_DEBUG_OBJECT (decoder, "Offset of last chunk %" G_GUINT64_FORMAT, u64);
-
-  /* pixel data */
-
-  /* go to the last pixel data chunk */
-  if (!gst_byte_reader_set_pos (&reader, u64))
-    goto need_more_data;
-
-  /* and read its size and skip it */
-  if (single_tile) {
-    if (!gst_byte_reader_skip (&reader, 4 * 4))
-      goto need_more_data;
-    if (!gst_byte_reader_get_uint32_le (&reader, &u32))
-      goto need_more_data;
-    if (!gst_byte_reader_skip (&reader, u32))
-      goto need_more_data;
-  } else {
-    if (!gst_byte_reader_skip (&reader, 4))
-      goto need_more_data;
-    if (!gst_byte_reader_get_uint32_le (&reader, &u32))
-      goto need_more_data;
-    if (!gst_byte_reader_skip (&reader, u32))
-      goto need_more_data;
+    size = offset;
   }
 
-  GST_DEBUG_OBJECT (decoder, "Have complete image of size %u",
-      gst_byte_reader_get_pos (&reader));
+  GST_DEBUG_OBJECT (decoder, "Have complete image of size %" G_GSSIZE_FORMAT, size);
 
-  gst_video_decoder_add_to_frame (decoder, gst_byte_reader_get_pos (&reader));
+  gst_video_decoder_add_to_frame (decoder, size);
 
   return gst_video_decoder_have_frame (decoder);