From 90211198a936ca7087dbf04e5d636fd9992a8332 Mon Sep 17 00:00:00 2001 From: Jerome Martinez Date: Wed, 22 Jan 2025 16:08:18 +0100 Subject: [PATCH 2/4] avformat/dat: improve DAT demuxer Less false positive detection Better computation of data size with 12-bit --- libavformat/dat.c | 49 ++++++++++++++++++++++++++++++++++------------- 1 file changed, 36 insertions(+), 13 deletions(-) diff --git a/libavformat/dat.c b/libavformat/dat.c index 37548a8a73..071af9a12a 100644 --- a/libavformat/dat.c +++ b/libavformat/dat.c @@ -26,8 +26,9 @@ #define DAT_PACKET_SIZE 5822 #define DAT_OFFSET 5760 -static const uint32_t encoded_rate[] = { 48000, 44100, 32000, 0 }; -static const uint16_t encoded_size[] = { 5760, 5292, 3840, 0 }; +static const uint16_t encoded_samples[] = { 1440, 1323, 960, 0 }; +static const uint8_t encoded_samples_mul[] = { 1, 2, 0, 0 }; +static const uint8_t encoded_quantization[] = { 16, 12, 0, 0 }; static const uint8_t encoded_chans[] = { 2, 4, 0, 0 }; static const enum AVCodecID encoded_codec[] = { AV_CODEC_ID_PCM_S16LE, @@ -41,12 +42,26 @@ static int valid_frame(uint8_t *frame) uint8_t *mainid = subid+4; int chan_index = (mainid[0] >> 0) & 0x3; int rate_index = (mainid[0] >> 2) & 0x3; + int fmtid = (mainid[0] >> 6) & 0x3; + int trackpitch = (mainid[1] >> 2) & 0x3; int enc_index = (mainid[1] >> 6) & 0x3; int dataid = (subid[0] >> 0) & 0xf; - - if (dataid != 0 || encoded_codec[enc_index] == AV_CODEC_ID_NONE || + int numpacks = (subid[1] >> 0) & 0xf; + int pno1 = (subid[1] >> 4) & 0xf; + int pno3 = (subid[2] >> 0) & 0xf; + int pno2 = (subid[2] >> 4) & 0xf; + int pno = (pno1 << 8) | (pno2 << 4) | pno3; + int encoded_size = encoded_samples[rate_index] * encoded_samples_mul[trackpitch] * encoded_chans[chan_index] * encoded_quantization[enc_index] / 8; + + if (dataid != 0 || + numpacks > 7 || + pno == 0 || encoded_chans[chan_index] == 0 || - encoded_rate[rate_index] == 0) + encoded_samples[rate_index] == 0 || + fmtid != 0 || + encoded_samples_mul[trackpitch] == 0 || + encoded_quantization[enc_index] == 0 || + encoded_size > DAT_OFFSET) return 0; return 1; @@ -62,7 +77,7 @@ static int read_probe(const AVProbeData *p) score += ret; if (ret == 0) - break; + return 0; } return FFMIN(score, AVPROBE_SCORE_MAX); @@ -82,21 +97,29 @@ static int parse_frame(uint8_t *frame, AVCodecParameters *par) uint8_t *mainid = subid+4; int chan_index = (mainid[0] >> 0) & 0x3; int rate_index = (mainid[0] >> 2) & 0x3; + int fmtid = (mainid[0] >> 6) & 0x3; + int trackpitch = (mainid[1] >> 2) & 0x3; int enc_index = (mainid[1] >> 6) & 0x3; int dataid = (subid[0] >> 0) & 0xf; + int encoded_size = 0; + int encoded_size = encoded_samples[rate_index] * encoded_samples_mul[trackpitch] * encoded_chans[chan_index] * encoded_quantization[enc_index] / 8; par->codec_type = AVMEDIA_TYPE_AUDIO; par->codec_id = encoded_codec[enc_index]; av_channel_layout_default(&par->ch_layout, encoded_chans[chan_index]); - par->sample_rate = encoded_rate[rate_index]; - par->bit_rate = (8LL * DAT_PACKET_SIZE * par->sample_rate) / FFMAX(1, av_get_audio_frame_duration2(par, encoded_size[rate_index])); - - if (dataid != 0 || par->codec_id == AV_CODEC_ID_NONE || - par->ch_layout.nb_channels <= 0 || - par->sample_rate <= 0) + par->sample_rate = encoded_samples[rate_index] * 100 / 3; + par->bit_rate = (8LL * DAT_PACKET_SIZE * par->sample_rate) / FFMAX(1, av_get_audio_frame_duration2(par, encoded_size)); + + if (dataid != 0 || + par->ch_layout.nb_channels == 0 || + par->sample_rate == 0 || + fmtid != 0 || + encoded_samples_mul[trackpitch] == 0 || + encoded_quantization[enc_index] == 0 || + encoded_size > DAT_OFFSET) return AVERROR_INVALIDDATA; - return encoded_size[rate_index]; + return encoded_size; } static int read_packet(AVFormatContext *s, AVPacket *pkt) -- 2.46.0.windows.1