[vlc-commits] mux: add AV1 samples packing helper

[Francois Cartegnie]

vlc | branch: master | Francois Cartegnie <fcvlcdev at free.fr> | Thu Oct 11 15:23:01 2018 +0200| [76af282a149fd29ac303b8547c9832598cf95d52] | committer: Francois Cartegnie

mux: add AV1 samples packing helper

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=76af282a149fd29ac303b8547c9832598cf95d52
---

 modules/mux/av1_pack.h | 96 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)

diff --git a/modules/mux/av1_pack.h b/modules/mux/av1_pack.h
new file mode 100644
index 0000000000..d594b862c7
--- /dev/null
+++ b/modules/mux/av1_pack.h
@@ -0,0 +1,96 @@
+/*****************************************************************************
+ * av1_pack.h: AV1 sample packer
+ *****************************************************************************
+ * Copyright (C) 2018 VideoLabs, VLC authors and VideoLAN
+ *
+ * This program 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.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+#ifndef VLC_AV1_PACK_H
+#define VLC_AV1_PACK_H
+
+#include <vlc_common.h>
+#include <vlc_block.h>
+
+#include "../packetizer/av1_obu.h"
+
+/*
+    Strips unwanted OBU and last size field
+    AV1 ISOBMFF Mapping 2.4
+    https://aomediacodec.github.io/av1-isobmff/#sampleformat
+    Matroska/WebM
+    https://github.com/Matroska-Org/matroska-specification/blob/master/codec/av1.md
+*/
+
+static inline block_t *AV1_Pack_Sample(block_t *p_block)
+{
+    AV1_OBU_iterator_ctx_t ctx;
+    AV1_OBU_iterator_init(&ctx, p_block->p_buffer, p_block->i_buffer);
+    const uint8_t *p_obu = NULL; size_t i_obu;
+    while(AV1_OBU_iterate_next(&ctx, &p_obu, &i_obu))
+    {
+        switch(AV1_OBUGetType(p_obu))
+        {
+            /* drops */
+            case AV1_OBU_TEMPORAL_DELIMITER:
+            case AV1_OBU_PADDING:
+            case AV1_OBU_REDUNDANT_FRAME_HEADER:
+            case AV1_OBU_TILE_LIST:
+            {
+                size_t i_offset = p_obu - p_block->p_buffer;
+                if(i_offset < p_block->i_buffer - i_offset - i_obu)
+                {
+                    memmove(&p_block->p_buffer[i_obu], p_block->p_buffer, i_offset);
+                    p_block->p_buffer += i_obu;
+                    p_block->i_buffer -= i_obu;
+                }
+                else
+                {
+                    memmove(&p_block->p_buffer[i_offset], &p_obu[i_obu], i_obu);
+                    p_block->i_buffer -= i_obu;
+                }
+                AV1_OBU_iterator_init(&ctx, p_block->p_buffer,
+                                            p_block->i_buffer);
+                p_obu = NULL;
+            } break;
+            default:
+                break;
+        }
+    }
+
+    if(p_obu && AV1_OBUHasSizeField(p_obu))
+    {
+        const size_t i_offset = p_obu - p_block->p_buffer;
+        const uint8_t i_header = AV1_OBUHasExtensionField(p_obu) ? 2 : 1;
+        uint8_t i_len = 0;
+        (void) AV1_OBUSize(p_obu, p_block->i_buffer - i_offset, &i_len);
+        if(i_len)
+        {
+            memmove(&p_block->p_buffer[i_offset + i_header],
+                    &p_block->p_buffer[i_offset + i_header + i_len],
+                    p_block->i_buffer - i_offset - i_header - i_len);
+            p_block->p_buffer[i_offset] &= 0xFD;
+            p_block->i_buffer -= i_len;
+        }
+    }
+
+    if(!p_block->i_buffer)
+    {
+        block_Release(p_block);
+        return NULL;
+    }
+    return p_block;
+}
+
+#endif