diff options
| -rw-r--r-- | libavcodec/apedec.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c index 2d1925018e..65c07d0f7f 100644 --- a/libavcodec/apedec.c +++ b/libavcodec/apedec.c @@ -24,6 +24,7 @@ #include "libavutil/avassert.h" #include "libavutil/channel_layout.h" +#include "libavutil/crc.h" #include "libavutil/opt.h" #include "lossless_audiodsp.h" #include "avcodec.h" @@ -147,7 +148,8 @@ typedef struct APEContext { int fset; ///< which filter set to use (calculated from compression level) int flags; ///< global decoder flags - uint32_t CRC; ///< frame CRC + uint32_t CRC; ///< signalled frame CRC + uint32_t CRC_state; ///< accumulated CRC int frameflags; ///< frame flags APEPredictor predictor; ///< predictor used for final reconstruction @@ -750,6 +752,7 @@ static int init_entropy_decoder(APEContext *ctx) /* Read the frame flags if they exist */ ctx->frameflags = 0; + ctx->CRC_state = UINT32_MAX; if ((ctx->fileversion > 3820) && (ctx->CRC & 0x80000000)) { ctx->CRC &= ~0x80000000; @@ -1577,6 +1580,27 @@ static int ape_decode_frame(AVCodecContext *avctx, void *data, s->samples -= blockstodecode; + if (avctx->err_recognition & AV_EF_CRCCHECK && + s->fileversion >= 3900 && s->bps < 24) { + uint32_t crc = s->CRC_state; + const AVCRC *crc_tab = av_crc_get_table(AV_CRC_32_IEEE_LE); + for (i = 0; i < blockstodecode; i++) { + for (ch = 0; ch < s->channels; ch++) { + uint8_t *smp = frame->data[ch] + (i*(s->bps >> 3)); + crc = av_crc(crc_tab, crc, smp, s->bps >> 3); + } + } + + if (!s->samples && (~crc >> 1) ^ s->CRC) { + av_log(avctx, AV_LOG_ERROR, "CRC mismatch! Previously decoded " + "frames may have been affected as well.\n"); + if (avctx->err_recognition & AV_EF_EXPLODE) + return AVERROR_INVALIDDATA; + } + + s->CRC_state = crc; + } + *got_frame_ptr = 1; return !s->samples ? avpkt->size : 0; |