| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /* | ||
| 2 | * RAW AC-4 demuxer | ||
| 3 | * Copyright (c) 2019 Paul B Mahol | ||
| 4 | * | ||
| 5 | * This file is part of FFmpeg. | ||
| 6 | * | ||
| 7 | * FFmpeg is free software; you can redistribute it and/or | ||
| 8 | * modify it under the terms of the GNU Lesser General Public | ||
| 9 | * License as published by the Free Software Foundation; either | ||
| 10 | * version 2.1 of the License, or (at your option) any later version. | ||
| 11 | * | ||
| 12 | * FFmpeg is distributed in the hope that it will be useful, | ||
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
| 15 | * Lesser General Public License for more details. | ||
| 16 | * | ||
| 17 | * You should have received a copy of the GNU Lesser General Public | ||
| 18 | * License along with FFmpeg; if not, write to the Free Software | ||
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
| 20 | */ | ||
| 21 | |||
| 22 | #include "libavutil/avassert.h" | ||
| 23 | #include "libavutil/crc.h" | ||
| 24 | #include "avformat.h" | ||
| 25 | #include "demux.h" | ||
| 26 | #include "rawdec.h" | ||
| 27 | |||
| 28 | 7148 | static int ac4_probe(const AVProbeData *p) | |
| 29 | { | ||
| 30 | 7148 | const uint8_t *buf = p->buf; | |
| 31 | 7148 | int left = p->buf_size; | |
| 32 | 7148 | int max_frames = 0; | |
| 33 | |||
| 34 |
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7148 | while (left > 7) { |
| 35 | int size; | ||
| 36 | |||
| 37 |
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7148 | if (buf[0] == 0xAC && |
| 38 | ✗ | (buf[1] == 0x40 || | |
| 39 | ✗ | buf[1] == 0x41)) { | |
| 40 | ✗ | size = (buf[2] << 8) | buf[3]; | |
| 41 | ✗ | if (size == 0xFFFF) | |
| 42 | ✗ | size = 3 + ((buf[4] << 16) | (buf[5] << 8) | buf[6]); | |
| 43 | ✗ | size += 4; | |
| 44 | ✗ | if (buf[1] == 0x41) | |
| 45 | ✗ | size += 2; | |
| 46 | ✗ | if (left < size) | |
| 47 | ✗ | break; | |
| 48 | ✗ | max_frames++; | |
| 49 | ✗ | left -= size; | |
| 50 | ✗ | buf += size; | |
| 51 | } else { | ||
| 52 | break; | ||
| 53 | } | ||
| 54 | } | ||
| 55 | |||
| 56 | 7148 | return FFMIN(AVPROBE_SCORE_MAX, max_frames * 7); | |
| 57 | } | ||
| 58 | |||
| 59 | ✗ | static int ac4_read_header(AVFormatContext *s) | |
| 60 | { | ||
| 61 | AVStream *st; | ||
| 62 | |||
| 63 | ✗ | st = avformat_new_stream(s, NULL); | |
| 64 | ✗ | if (!st) | |
| 65 | ✗ | return AVERROR(ENOMEM); | |
| 66 | |||
| 67 | ✗ | st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; | |
| 68 | ✗ | st->codecpar->codec_id = AV_CODEC_ID_AC4; | |
| 69 | |||
| 70 | ✗ | return 0; | |
| 71 | } | ||
| 72 | |||
| 73 | ✗ | static int ac4_read_packet(AVFormatContext *s, AVPacket *pkt) | |
| 74 | { | ||
| 75 | ✗ | AVIOContext *pb = s->pb; | |
| 76 | int64_t pos; | ||
| 77 | uint16_t sync; | ||
| 78 | int ret, size; | ||
| 79 | |||
| 80 | ✗ | if (avio_feof(s->pb)) | |
| 81 | ✗ | return AVERROR_EOF; | |
| 82 | |||
| 83 | ✗ | pos = avio_tell(s->pb); | |
| 84 | ✗ | sync = avio_rb16(pb); | |
| 85 | ✗ | size = avio_rb16(pb); | |
| 86 | ✗ | if (size == 0xffff) | |
| 87 | ✗ | size = avio_rb24(pb); | |
| 88 | |||
| 89 | ✗ | ret = av_get_packet(pb, pkt, size); | |
| 90 | ✗ | pkt->pos = pos; | |
| 91 | ✗ | pkt->stream_index = 0; | |
| 92 | |||
| 93 | ✗ | if (sync == 0xAC41) | |
| 94 | ✗ | avio_skip(pb, 2); | |
| 95 | |||
| 96 | ✗ | return ret; | |
| 97 | } | ||
| 98 | |||
| 99 | const FFInputFormat ff_ac4_demuxer = { | ||
| 100 | .p.name = "ac4", | ||
| 101 | .p.long_name = NULL_IF_CONFIG_SMALL("raw AC-4"), | ||
| 102 | .p.flags = AVFMT_GENERIC_INDEX, | ||
| 103 | .p.extensions = "ac4", | ||
| 104 | .read_probe = ac4_probe, | ||
| 105 | .read_header = ac4_read_header, | ||
| 106 | .read_packet = ac4_read_packet, | ||
| 107 | }; | ||
| 108 |