hevc_parse: rename into h2645_parse

This code will be shared with h264.

1 files changed, 228 insertions, 0 deletions

diff --git a/libavcodec/h2645_parse.c b/libavcodec/h2645_parse.c
new file mode 100644
index 0000000..794c954
--- /dev/null
+++ b/libavcodec/h2645_parse.c
@@ -0,0 +1,228 @@
+/*
+ * H.264/HEVC common parsing code
+ *
+ * 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
+ */
+
+#include <string.h>
+
+#include "config.h"
+
+#include "libavutil/intreadwrite.h"
+#include "libavutil/mem.h"
+
+#include "h2645_parse.h"
+
+/* FIXME: This is adapted from ff_h264_decode_nal, avoiding duplication
+ * between these functions would be nice. */
+int ff_h2645_extract_rbsp(const uint8_t *src, int length,
+                          H2645NAL *nal)
+{
+    int i, si, di;
+    uint8_t *dst;
+
+#define STARTCODE_TEST                                                  \
+        if (i + 2 < length && src[i + 1] == 0 && src[i + 2] <= 3) {     \
+            if (src[i + 2] != 3) {                                      \
+                /* startcode, so we must be past the end */             \
+                length = i;                                             \
+            }                                                           \
+            break;                                                      \
+        }
+#if HAVE_FAST_UNALIGNED
+#define FIND_FIRST_ZERO                                                 \
+        if (i > 0 && !src[i])                                           \
+            i--;                                                        \
+        while (src[i])                                                  \
+            i++
+#if HAVE_FAST_64BIT
+    for (i = 0; i + 1 < length; i += 9) {
+        if (!((~AV_RN64A(src + i) &
+               (AV_RN64A(src + i) - 0x0100010001000101ULL)) &
+              0x8000800080008080ULL))
+            continue;
+        FIND_FIRST_ZERO;
+        STARTCODE_TEST;
+        i -= 7;
+    }
+#else
+    for (i = 0; i + 1 < length; i += 5) {
+        if (!((~AV_RN32A(src + i) &
+               (AV_RN32A(src + i) - 0x01000101U)) &
+              0x80008080U))
+            continue;
+        FIND_FIRST_ZERO;
+        STARTCODE_TEST;
+        i -= 3;
+    }
+#endif /* HAVE_FAST_64BIT */
+#else
+    for (i = 0; i + 1 < length; i += 2) {
+        if (src[i])
+            continue;
+        if (i > 0 && src[i - 1] == 0)
+            i--;
+        STARTCODE_TEST;
+    }
+#endif /* HAVE_FAST_UNALIGNED */
+
+    if (i >= length - 1) { // no escaped 0
+        nal->data     =
+        nal->raw_data = src;
+        nal->size     =
+        nal->raw_size = length;
+        return length;
+    }
+
+    av_fast_malloc(&nal->rbsp_buffer, &nal->rbsp_buffer_size,
+                   length + AV_INPUT_BUFFER_PADDING_SIZE);
+    if (!nal->rbsp_buffer)
+        return AVERROR(ENOMEM);
+
+    dst = nal->rbsp_buffer;
+
+    memcpy(dst, src, i);
+    si = di = i;
+    while (si + 2 < length) {
+        // remove escapes (very rare 1:2^22)
+        if (src[si + 2] > 3) {
+            dst[di++] = src[si++];
+            dst[di++] = src[si++];
+        } else if (src[si] == 0 && src[si + 1] == 0) {
+            if (src[si + 2] == 3) { // escape
+                dst[di++] = 0;
+                dst[di++] = 0;
+                si       += 3;
+
+                continue;
+            } else // next start code
+                goto nsc;
+        }
+
+        dst[di++] = src[si++];
+    }
+    while (si < length)
+        dst[di++] = src[si++];
+
+nsc:
+    memset(dst + di, 0, AV_INPUT_BUFFER_PADDING_SIZE);
+
+    nal->data = dst;
+    nal->size = di;
+    nal->raw_data = src;
+    nal->raw_size = si;
+    return si;
+}
+
+/**
+ * @return AVERROR_INVALIDDATA if the packet is not a valid NAL unit,
+ * 0 if the unit should be skipped, 1 otherwise
+ */
+static int hevc_parse_nal_header(H2645NAL *nal, AVCodecContext *avctx)
+{
+    GetBitContext *gb = &nal->gb;
+    int nuh_layer_id;
+
+    if (get_bits1(gb) != 0)
+        return AVERROR_INVALIDDATA;
+
+    nal->type = get_bits(gb, 6);
+
+    nuh_layer_id   = get_bits(gb, 6);
+    nal->temporal_id = get_bits(gb, 3) - 1;
+    if (nal->temporal_id < 0)
+        return AVERROR_INVALIDDATA;
+
+    av_log(avctx, AV_LOG_DEBUG,
+           "nal_unit_type: %d, nuh_layer_id: %dtemporal_id: %d\n",
+           nal->type, nuh_layer_id, nal->temporal_id);
+
+    return nuh_layer_id == 0;
+}
+
+
+int ff_h2645_packet_split(H2645Packet *pkt, const uint8_t *buf, int length,
+                          AVCodecContext *avctx, int is_nalff, int nal_length_size)
+{
+    int consumed, ret = 0;
+
+    pkt->nb_nals = 0;
+    while (length >= 4) {
+        H2645NAL *nal;
+        int extract_length = 0;
+
+        if (is_nalff) {
+            int i;
+            for (i = 0; i < nal_length_size; i++)
+                extract_length = (extract_length << 8) | buf[i];
+            buf    += nal_length_size;
+            length -= nal_length_size;
+
+            if (extract_length > length) {
+                av_log(avctx, AV_LOG_ERROR, "Invalid NAL unit size.\n");
+                return AVERROR_INVALIDDATA;
+            }
+        } else {
+            if (buf[2] == 0) {
+                length--;
+                buf++;
+                continue;
+            }
+            if (buf[0] != 0 || buf[1] != 0 || buf[2] != 1)
+                return AVERROR_INVALIDDATA;
+
+            buf           += 3;
+            length        -= 3;
+            extract_length = length;
+        }
+
+        if (pkt->nals_allocated < pkt->nb_nals + 1) {
+            int new_size = pkt->nals_allocated + 1;
+            H2645NAL *tmp = av_realloc_array(pkt->nals, new_size, sizeof(*tmp));
+            if (!tmp)
+                return AVERROR(ENOMEM);
+
+            pkt->nals = tmp;
+            memset(pkt->nals + pkt->nals_allocated, 0,
+                   (new_size - pkt->nals_allocated) * sizeof(*tmp));
+            pkt->nals_allocated = new_size;
+        }
+        nal = &pkt->nals[pkt->nb_nals++];
+
+        consumed = ff_h2645_extract_rbsp(buf, extract_length, nal);
+        if (consumed < 0)
+            return consumed;
+
+        ret = init_get_bits8(&nal->gb, nal->data, nal->size);
+        if (ret < 0)
+            return ret;
+
+        ret = hevc_parse_nal_header(nal, avctx);
+        if (ret <= 0) {
+            if (ret < 0) {
+                av_log(avctx, AV_LOG_ERROR, "Invalid NAL unit %d, skipping.\n",
+                       nal->type);
+            }
+            pkt->nb_nals--;
+        }
+
+        buf    += consumed;
+        length -= consumed;
+    }
+
+    return 0;
+}