lavc: add a HEVC decoder.

Initially written by Guillaume Martres <smarter@ubuntu.com> as a GSoC
project. Further contributions by the OpenHEVC project and other
developers, namely:

Mickaël Raulet <mraulet@insa-rennes.fr>
Seppo Tomperi <seppo.tomperi@vtt.fi>
Gildas Cocherel <gildas.cocherel@laposte.net>
Khaled Jerbi <khaled_jerbi@yahoo.fr>
Wassim Hamidouche <wassim.hamidouche@insa-rennes.fr>
Vittorio Giovara <vittorio.giovara@gmail.com>
Jan Ekström <jeebjp@gmail.com>
Anton Khirnov <anton@khirnov.net>
Martin Storsjö <martin@martin.st>
Luca Barbato <lu_zero@gentoo.org>
Yusuke Nakamura <muken.the.vfrmaniac@gmail.com>

Signed-off-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 125 insertions, 0 deletions

diff --git a/libavcodec/hevc_parser.c b/libavcodec/hevc_parser.c
new file mode 100644
index 0000000000..7e038bea0c
--- /dev/null
+++ b/libavcodec/hevc_parser.c
@@ -0,0 +1,125 @@
+/*
+ * HEVC Annex B format parser
+ *
+ * Copyright (C) 2012 - 2013 Guillaume Martres
+ *
+ * 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 "libavutil/common.h"
+#include "parser.h"
+#include "hevc.h"
+
+#define START_CODE 0x000001 ///< start_code_prefix_one_3bytes
+
+/**
+ * Find the end of the current frame in the bitstream.
+ * @return the position of the first byte of the next frame, or END_NOT_FOUND
+ */
+static int hevc_find_frame_end(AVCodecParserContext *s, const uint8_t *buf, int buf_size)
+{
+    int i;
+    ParseContext *pc = s->priv_data;
+
+    for (i = 0; i < buf_size; i++) {
+        int nut;
+
+        pc->state64 = (pc->state64 << 8) | buf[i];
+
+        if (((pc->state64 >> 3 * 8) & 0xFFFFFF) != START_CODE)
+            continue;
+
+        nut = (pc->state64 >> 2 * 8 + 1) & 0x3F;
+        // Beginning of access unit
+        if ((nut >= NAL_VPS && nut <= NAL_AUD) || nut == NAL_SEI_PREFIX ||
+            (nut >= 41 && nut <= 44) || (nut >= 48 && nut <= 55)) {
+            if (pc->frame_start_found) {
+                pc->frame_start_found = 0;
+                return i - 5;
+            }
+        } else if (nut <= NAL_RASL_R ||
+                   (nut >= NAL_BLA_W_LP && nut <= NAL_CRA_NUT)) {
+            int first_slice_segment_in_pic_flag = buf[i] >> 7;
+            if (first_slice_segment_in_pic_flag) {
+                if (!pc->frame_start_found) {
+                    pc->frame_start_found = 1;
+                    s->key_frame = nut >= NAL_BLA_W_LP && nut <= NAL_CRA_NUT;
+                } else { // First slice of next frame found
+                    pc->frame_start_found = 0;
+                    return i - 5;
+                }
+            }
+        }
+    }
+
+    return END_NOT_FOUND;
+}
+
+static int hevc_parse(AVCodecParserContext *s,
+                      AVCodecContext *avctx,
+                      const uint8_t **poutbuf, int *poutbuf_size,
+                      const uint8_t *buf, int buf_size)
+{
+    int next;
+    ParseContext *pc = s->priv_data;
+
+    if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
+        next = buf_size;
+    } else {
+        next = hevc_find_frame_end(s, buf, buf_size);
+        if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
+            *poutbuf = NULL;
+            *poutbuf_size = 0;
+            return buf_size;
+        }
+    }
+
+    *poutbuf = buf;
+    *poutbuf_size = buf_size;
+    return next;
+}
+
+// Split after the parameter sets at the beginning of the stream if they exist.
+static int hevc_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
+{
+    int i;
+    uint32_t state = -1;
+    int has_ps = 0;
+
+    for (i = 0; i < buf_size; i++) {
+        state = (state << 8) | buf[i];
+        if (((state >> 8) & 0xFFFFFF) == START_CODE) {
+            int nut = (state >> 1) & 0x3F;
+            if (nut >= NAL_VPS && nut <= NAL_PPS) {
+                has_ps = 1;
+            } else if (has_ps) {
+                return i - 3;
+            } else { // no parameter set at the beginning of the stream
+                return 0;
+            }
+        }
+    }
+    return 0;
+}
+
+AVCodecParser ff_hevc_parser = {
+    .codec_ids      = { AV_CODEC_ID_HEVC },
+    .priv_data_size = sizeof(ParseContext),
+    .parser_parse   = hevc_parse,
+    .parser_close   = ff_parse_close,
+    .split          = hevc_split,
+};