From 2a72b1664d7bfde3ad624c140519396b2e31c7fe Mon Sep 17 00:00:00 2001 From: Zhaoxiu Zeng Date: Fri, 13 Feb 2015 13:51:30 +0800 Subject: [PATCH] avcodec/h264: use avpriv_find_start_code() in h264_split() This also allows replacing several literal numbers by named constants And it should be faster, the function is not speed relevant though as it is generally only called a few times at the streams start. Signed-off-by: Michael Niedermayer --- libavcodec/h264_parser.c | 35 +++++++++++++++++++---------------- 1 file changed, 19 insertions(+), 16 deletions(-) diff --git a/libavcodec/h264_parser.c b/libavcodec/h264_parser.c index b1815e6d45..ac593e63c1 100644 --- a/libavcodec/h264_parser.c +++ b/libavcodec/h264_parser.c @@ -526,34 +526,37 @@ static int h264_parse(AVCodecParserContext *s, static int h264_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size) { - int i; uint32_t state = -1; int has_sps = 0; int has_pps = 0; + const uint8_t *ptr = buf, *end = buf + buf_size; + int nalu_type; - for (i = 0; i <= buf_size; i++) { - if ((state & 0xFFFFFF1F) == 0x107) + while (ptr < end) { + ptr = avpriv_find_start_code(ptr, end, &state); + if ((state & 0xFFFFFF00) != 0x100) + break; + nalu_type = state & 0x1F; + if (nalu_type == NAL_SPS) { has_sps = 1; - if ((state & 0xFFFFFF1F) == 0x108) + } else if (nalu_type == NAL_PPS) has_pps = 1; - /* if ((state&0xFFFFFF1F) == 0x101 || - * (state&0xFFFFFF1F) == 0x102 || - * (state&0xFFFFFF1F) == 0x105) { + /* else if (nalu_type == 0x01 || + * nalu_type == 0x02 || + * nalu_type == 0x05) { * } */ - if ((state & 0xFFFFFF00) == 0x100 && ((state & 0xFFFFFF1F) != 0x106 || has_pps) && - (state & 0xFFFFFF1F) != 0x107 && (state & 0xFFFFFF1F) != 0x108 && - (state & 0xFFFFFF1F) != 0x109 && (state & 0xFFFFFF1F) != 0x10d && - (state & 0xFFFFFF1F) != 0x10f) { + else if ((nalu_type != NAL_SEI || has_pps) && + nalu_type != NAL_AUD && nalu_type != NAL_SPS_EXT && + nalu_type != 0x0f) { if (has_sps) { - while (i > 4 && buf[i - 5] == 0) - i--; - return i - 4; + while (ptr - 4 > buf && ptr[-5] == 0) + ptr--; + return ptr - 4 - buf; } } - if (i < buf_size) - state = (state << 8) | buf[i]; } + return 0; }