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author | Michael Niedermayer <michaelni@gmx.at> | 2015-07-09 06:04:13 +0300 |
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committer | Michael Niedermayer <michaelni@gmx.at> | 2015-07-09 06:06:48 +0300 |
commit | 07ae8fa20ef202206157efebf0a09db9a9cb9634 (patch) | |
tree | 75e15cb455b62eac5a0dff6e95cd90ffe2a99e08 /libavcodec/hevc_parse.c | |
parent | 1dacf26964c9a65380ca615d1fc09302218a539e (diff) | |
parent | 69ab9f53f901eac6a649e22d28cf093357870627 (diff) |
Merge commit '69ab9f53f901eac6a649e22d28cf093357870627'
* commit '69ab9f53f901eac6a649e22d28cf093357870627':
hevc: split bitstream unescaping to a separate file
Conflicts:
libavcodec/Makefile
libavcodec/hevc.c
See: afa93d198aaf2cc661c4df6d4095cd030265d30a
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'libavcodec/hevc_parse.c')
-rw-r--r-- | libavcodec/hevc_parse.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/libavcodec/hevc_parse.c b/libavcodec/hevc_parse.c new file mode 100644 index 0000000000..260f1e1aa6 --- /dev/null +++ b/libavcodec/hevc_parse.c @@ -0,0 +1,145 @@ +/* + * HEVC common code + * + * 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 <string.h> + +#include "config.h" + +#include "libavutil/intreadwrite.h" +#include "libavutil/mem.h" + +#include "hevc.h" + +/* FIXME: This is adapted from ff_h264_decode_nal, avoiding duplication + * between these functions would be nice. */ +int ff_hevc_extract_rbsp(HEVCContext *s, const uint8_t *src, int length, + HEVCNAL *nal) +{ + int i, si, di; + uint8_t *dst; + + if (s) + s->skipped_bytes = 0; +#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 + FF_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; + + if (s) { + s->skipped_bytes++; + if (s->skipped_bytes_pos_size < s->skipped_bytes) { + s->skipped_bytes_pos_size *= 2; + av_reallocp_array(&s->skipped_bytes_pos, + s->skipped_bytes_pos_size, + sizeof(*s->skipped_bytes_pos)); + if (!s->skipped_bytes_pos) + return AVERROR(ENOMEM); + } + if (s->skipped_bytes_pos) + s->skipped_bytes_pos[s->skipped_bytes-1] = di - 1; + } + continue; + } else // next start code + goto nsc; + } + + dst[di++] = src[si++]; + } + while (si < length) + dst[di++] = src[si++]; + +nsc: + memset(dst + di, 0, FF_INPUT_BUFFER_PADDING_SIZE); + + nal->data = dst; + nal->size = di; + nal->raw_data = src; + nal->raw_size = si; + return si; +} + |