diff options
| author | Lynne <dev@lynne.ee> | 2019-03-06 17:04:04 +0000 |
|---|---|---|
| committer | Lynne <dev@lynne.ee> | 2020-05-26 10:23:11 +0100 |
| commit | e69f407b52110387800ee0531aa78e213b214150 (patch) | |
| tree | 7160f050b15527bafcfd570f0c5845ffe1ef3ffa | |
| parent | 1cc8eecd3844ede71224edcbdd67ebca505146ba (diff) | |
mpegaudiodec_template: add ability to check CRC
A lot of files have CRC included.
The CRC only covers 34 bytes at most from the frame but it should still be
enough for some amount of error detection.
| -rw-r--r-- | libavcodec/mpegaudiodec_template.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/libavcodec/mpegaudiodec_template.c b/libavcodec/mpegaudiodec_template.c index 3f1674e827..3d7e3ba4f2 100644 --- a/libavcodec/mpegaudiodec_template.c +++ b/libavcodec/mpegaudiodec_template.c @@ -27,6 +27,7 @@ #include "libavutil/attributes.h" #include "libavutil/avassert.h" #include "libavutil/channel_layout.h" +#include "libavutil/crc.h" #include "libavutil/float_dsp.h" #include "libavutil/libm.h" #include "avcodec.h" @@ -1565,9 +1566,22 @@ static int mp_decode_frame(MPADecodeContext *s, OUT_INT **samples, init_get_bits(&s->gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE) * 8); - /* skip error protection field */ - if (s->error_protection) - skip_bits(&s->gb, 16); + if (s->error_protection) { + uint16_t crc = get_bits(&s->gb, 16); + if (s->err_recognition & AV_EF_CRCCHECK) { + const int sec_len = s->lsf ? ((s->nb_channels == 1) ? 9 : 17) : + ((s->nb_channels == 1) ? 17 : 32); + const AVCRC *crc_tab = av_crc_get_table(AV_CRC_16_ANSI); + uint32_t crc_cal = av_crc(crc_tab, UINT16_MAX, &buf[2], 2); + crc_cal = av_crc(crc_tab, crc_cal, &buf[6], sec_len); + + if (av_bswap16(crc) ^ crc_cal) { + av_log(s->avctx, AV_LOG_ERROR, "CRC mismatch!\n"); + if (s->err_recognition & AV_EF_EXPLODE) + return AVERROR_INVALIDDATA; + } + } + } switch(s->layer) { case 1: |