From 80ea66112817c719b476de8f7d8d3b325f4c7dd1 Mon Sep 17 00:00:00 2001 From: David Holm Date: Fri, 31 Jul 2015 21:06:13 +0200 Subject: avcodec: h264: Extract decoder methods Extract two methods from decode_registered_user_data in order to improve code readability. Also make the constant holding the allocation size a 64-bit unsigned integer so that the size comparison against INT_MAX makes sense. Bug-Id: CID1312090 Signed-off-by: Luca Barbato --- libavcodec/h264_sei.c | 124 ++++++++++++++++++++++++++++---------------------- 1 file changed, 70 insertions(+), 54 deletions(-) (limited to 'libavcodec/h264_sei.c') diff --git a/libavcodec/h264_sei.c b/libavcodec/h264_sei.c index 1f3844b28e..8b07682c7e 100644 --- a/libavcodec/h264_sei.c +++ b/libavcodec/h264_sei.c @@ -106,11 +106,78 @@ static int decode_picture_timing(H264Context *h) return 0; } +static int decode_registered_user_data_afd(H264Context *h, int size) +{ + int flag; + + if (size-- < 1) + return AVERROR_INVALIDDATA; + skip_bits(&h->gb, 1); // 0 + flag = get_bits(&h->gb, 1); // active_format_flag + skip_bits(&h->gb, 6); // reserved + + if (flag) { + if (size-- < 1) + return AVERROR_INVALIDDATA; + skip_bits(&h->gb, 4); // reserved + h->active_format_description = get_bits(&h->gb, 4); + h->sei_reguserdata_afd_present = 1; + } + + return 0; +} + +static int decode_registered_user_data_closed_caption(H264Context *h, int size) +{ + int flag; + int user_data_type_code; + int cc_count; + + if (size < 3) + return AVERROR(EINVAL); + + user_data_type_code = get_bits(&h->gb, 8); + if (user_data_type_code == 0x3) { + skip_bits(&h->gb, 1); // reserved + + flag = get_bits(&h->gb, 1); // process_cc_data_flag + if (flag) { + skip_bits(&h->gb, 1); // zero bit + cc_count = get_bits(&h->gb, 5); + skip_bits(&h->gb, 8); // reserved + size -= 2; + + if (cc_count && size >= cc_count * 3) { + const uint64_t new_size = (h->a53_caption_size + cc_count + * UINT64_C(3)); + int i, ret; + + if (new_size > INT_MAX) + return AVERROR(EINVAL); + + /* Allow merging of the cc data from two fields. */ + ret = av_reallocp(&h->a53_caption, new_size); + if (ret < 0) + return ret; + + for (i = 0; i < cc_count; i++) { + h->a53_caption[h->a53_caption_size++] = get_bits(&h->gb, 8); + h->a53_caption[h->a53_caption_size++] = get_bits(&h->gb, 8); + h->a53_caption[h->a53_caption_size++] = get_bits(&h->gb, 8); + } + + skip_bits(&h->gb, 8); // marker_bits + } + } + } + + return 0; +} + static int decode_registered_user_data(H264Context *h, int size) { uint32_t country_code; uint32_t user_identifier; - int flag, user_data_type_code, cc_count; if (size < 7) return AVERROR_INVALIDDATA; @@ -129,60 +196,9 @@ static int decode_registered_user_data(H264Context *h, int size) switch (user_identifier) { case MKBETAG('D', 'T', 'G', '1'): // afd_data - if (size-- < 1) - return AVERROR_INVALIDDATA; - skip_bits(&h->gb, 1); // 0 - flag = get_bits(&h->gb, 1); // active_format_flag - skip_bits(&h->gb, 6); // reserved - - if (flag) { - if (size-- < 1) - return AVERROR_INVALIDDATA; - skip_bits(&h->gb, 4); // reserved - h->active_format_description = get_bits(&h->gb, 4); - h->sei_reguserdata_afd_present = 1; - } - break; + return decode_registered_user_data_afd(h, size); case MKBETAG('G', 'A', '9', '4'): // closed captions - if (size < 3) - return AVERROR(EINVAL); - - user_data_type_code = get_bits(&h->gb, 8); - if (user_data_type_code == 0x3) { - skip_bits(&h->gb, 1); // reserved - - flag = get_bits(&h->gb, 1); // process_cc_data_flag - if (flag) { - skip_bits(&h->gb, 1); // zero bit - cc_count = get_bits(&h->gb, 5); - skip_bits(&h->gb, 8); // reserved - size -= 2; - - if (cc_count && size >= cc_count * 3) { - int i, ret; - int new_size = (int64_t) h->a53_caption_size + - (int64_t) cc_count * 3; - - if (new_size > INT_MAX) - return AVERROR(EINVAL); - - /* Allow merging of the cc data from two fields. */ - ret = av_reallocp(&h->a53_caption, - h->a53_caption_size + cc_count * 3); - if (ret < 0) - return ret; - - for (i = 0; i < cc_count; i++) { - h->a53_caption[h->a53_caption_size++] = get_bits(&h->gb, 8); - h->a53_caption[h->a53_caption_size++] = get_bits(&h->gb, 8); - h->a53_caption[h->a53_caption_size++] = get_bits(&h->gb, 8); - } - - skip_bits(&h->gb, 8); // marker_bits - } - } - } - break; + return decode_registered_user_data_closed_caption(h, size); default: skip_bits(&h->gb, size * 8); break; -- cgit v1.2.3