diff options
Diffstat (limited to 'libavcodec/mpeg4_unpack_bframes_bsf.c')
| -rw-r--r-- | libavcodec/mpeg4_unpack_bframes_bsf.c | 34 |
1 files changed, 10 insertions, 24 deletions
diff --git a/libavcodec/mpeg4_unpack_bframes_bsf.c b/libavcodec/mpeg4_unpack_bframes_bsf.c index e9c535f390..1daf133ce5 100644 --- a/libavcodec/mpeg4_unpack_bframes_bsf.c +++ b/libavcodec/mpeg4_unpack_bframes_bsf.c @@ -21,50 +21,36 @@ #include "avcodec.h" #include "bsf.h" +#include "internal.h" #include "mpeg4video.h" typedef struct UnpackBFramesBSFContext { AVPacket *b_frame; } UnpackBFramesBSFContext; -/* search next start code */ -static unsigned int find_startcode(const uint8_t *buf, int buf_size, int *pos) -{ - unsigned int startcode = 0xFF; - - for (; *pos < buf_size;) { - startcode = ((startcode << 8) | buf[*pos]) & 0xFFFFFFFF; - *pos +=1; - if ((startcode & 0xFFFFFF00) != 0x100) - continue; /* no startcode */ - return startcode; - } - - return 0; -} - /* determine the position of the packed marker in the userdata, * the number of VOPs and the position of the second VOP */ static void scan_buffer(const uint8_t *buf, int buf_size, int *pos_p, int *nb_vop, int *pos_vop2) { - unsigned int startcode; - int pos, i; + uint32_t startcode; + const uint8_t *end = buf + buf_size, *pos = buf; - for (pos = 0; pos < buf_size;) { - startcode = find_startcode(buf, buf_size, &pos); + while (pos < end) { + startcode = -1; + pos = avpriv_find_start_code(pos, end, &startcode); if (startcode == USER_DATA_STARTCODE && pos_p) { /* check if the (DivX) userdata string ends with 'p' (packed) */ - for (i = 0; i < 255 && pos + i + 1 < buf_size; i++) { - if (buf[pos + i] == 'p' && buf[pos + i + 1] == '\0') { - *pos_p = pos + i; + for (int i = 0; i < 255 && pos + i + 1 < end; i++) { + if (pos[i] == 'p' && pos[i + 1] == '\0') { + *pos_p = pos + i - buf; break; } } } else if (startcode == VOP_STARTCODE && nb_vop) { *nb_vop += 1; if (*nb_vop == 2 && pos_vop2) { - *pos_vop2 = pos - 4; /* subtract 4 bytes startcode */ + *pos_vop2 = pos - buf - 4; /* subtract 4 bytes startcode */ } } } |