| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /* | ||
| 2 | * HCOM audio decoder | ||
| 3 | * | ||
| 4 | * This file is part of FFmpeg. | ||
| 5 | * | ||
| 6 | * FFmpeg is free software; you can redistribute it and/or | ||
| 7 | * modify it under the terms of the GNU Lesser General Public | ||
| 8 | * License as published by the Free Software Foundation; either | ||
| 9 | * version 2.1 of the License, or (at your option) any later version. | ||
| 10 | * | ||
| 11 | * FFmpeg is distributed in the hope that it will be useful, | ||
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
| 14 | * Lesser General Public License for more details. | ||
| 15 | * | ||
| 16 | * You should have received a copy of the GNU Lesser General Public | ||
| 17 | * License along with FFmpeg; if not, write to the Free Software | ||
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
| 19 | */ | ||
| 20 | |||
| 21 | #include "libavutil/intreadwrite.h" | ||
| 22 | |||
| 23 | #include "avcodec.h" | ||
| 24 | #include "codec_internal.h" | ||
| 25 | #include "decode.h" | ||
| 26 | #include "get_bits.h" | ||
| 27 | |||
| 28 | typedef struct HEntry { | ||
| 29 | int16_t l, r; | ||
| 30 | } HEntry; | ||
| 31 | |||
| 32 | typedef struct HCOMContext { | ||
| 33 | AVCodecContext *avctx; | ||
| 34 | |||
| 35 | uint8_t first_sample; | ||
| 36 | uint8_t sample; | ||
| 37 | int dict_entries; | ||
| 38 | int dict_entry; | ||
| 39 | int delta_compression; | ||
| 40 | |||
| 41 | HEntry *dict; | ||
| 42 | } HCOMContext; | ||
| 43 | |||
| 44 | ✗ | static av_cold int hcom_init(AVCodecContext *avctx) | |
| 45 | { | ||
| 46 | ✗ | HCOMContext *s = avctx->priv_data; | |
| 47 | |||
| 48 | ✗ | if (avctx->ch_layout.nb_channels != 1) { | |
| 49 | ✗ | av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n"); | |
| 50 | ✗ | return AVERROR_INVALIDDATA; | |
| 51 | } | ||
| 52 | |||
| 53 | ✗ | if (avctx->extradata_size <= 7) | |
| 54 | ✗ | return AVERROR_INVALIDDATA; | |
| 55 | ✗ | s->dict_entries = AV_RB16(avctx->extradata); | |
| 56 | ✗ | if (avctx->extradata_size < s->dict_entries * 4 + 7 || | |
| 57 | ✗ | s->dict_entries == 0) | |
| 58 | ✗ | return AVERROR_INVALIDDATA; | |
| 59 | ✗ | s->delta_compression = AV_RB32(avctx->extradata + 2); | |
| 60 | ✗ | s->sample = s->first_sample = avctx->extradata[avctx->extradata_size - 1]; | |
| 61 | |||
| 62 | ✗ | s->dict = av_calloc(s->dict_entries, sizeof(*s->dict)); | |
| 63 | ✗ | if (!s->dict) | |
| 64 | ✗ | return AVERROR(ENOMEM); | |
| 65 | ✗ | for (int i = 0; i < s->dict_entries; i++) { | |
| 66 | ✗ | s->dict[i].l = AV_RB16(avctx->extradata + 6 + 4 * i); | |
| 67 | ✗ | s->dict[i].r = AV_RB16(avctx->extradata + 6 + 4 * i + 2); | |
| 68 | ✗ | if (s->dict[i].l >= 0 && | |
| 69 | ✗ | (s->dict[i].l >= s->dict_entries || | |
| 70 | ✗ | s->dict[i].r >= s->dict_entries || | |
| 71 | ✗ | s->dict[i].r < 0 )) | |
| 72 | ✗ | return AVERROR_INVALIDDATA; | |
| 73 | } | ||
| 74 | ✗ | if (s->dict[0].l < 0) | |
| 75 | ✗ | return AVERROR_INVALIDDATA; | |
| 76 | |||
| 77 | ✗ | avctx->sample_fmt = AV_SAMPLE_FMT_U8; | |
| 78 | ✗ | s->dict_entry = 0; | |
| 79 | |||
| 80 | ✗ | return 0; | |
| 81 | } | ||
| 82 | |||
| 83 | ✗ | static int hcom_decode(AVCodecContext *avctx, AVFrame *frame, | |
| 84 | int *got_frame, AVPacket *pkt) | ||
| 85 | { | ||
| 86 | ✗ | HCOMContext *s = avctx->priv_data; | |
| 87 | GetBitContext gb; | ||
| 88 | ✗ | int ret, n = 0; | |
| 89 | |||
| 90 | ✗ | if (pkt->size > INT16_MAX) | |
| 91 | ✗ | return AVERROR_INVALIDDATA; | |
| 92 | |||
| 93 | ✗ | frame->nb_samples = pkt->size * 8; | |
| 94 | ✗ | if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) | |
| 95 | ✗ | return ret; | |
| 96 | |||
| 97 | ✗ | if ((ret = init_get_bits8(&gb, pkt->data, pkt->size)) < 0) | |
| 98 | ✗ | return ret; | |
| 99 | |||
| 100 | ✗ | while (get_bits_left(&gb) > 0) { | |
| 101 | ✗ | if (get_bits1(&gb)) | |
| 102 | ✗ | s->dict_entry = s->dict[s->dict_entry].r; | |
| 103 | else | ||
| 104 | ✗ | s->dict_entry = s->dict[s->dict_entry].l; | |
| 105 | |||
| 106 | ✗ | if (s->dict[s->dict_entry].l < 0) { | |
| 107 | int16_t datum; | ||
| 108 | |||
| 109 | ✗ | datum = s->dict[s->dict_entry].r; | |
| 110 | |||
| 111 | ✗ | if (!s->delta_compression) | |
| 112 | ✗ | s->sample = 0; | |
| 113 | ✗ | s->sample = (s->sample + datum) & 0xFF; | |
| 114 | |||
| 115 | ✗ | frame->data[0][n++] = s->sample; | |
| 116 | |||
| 117 | ✗ | s->dict_entry = 0; | |
| 118 | } | ||
| 119 | } | ||
| 120 | |||
| 121 | ✗ | frame->nb_samples = n; | |
| 122 | |||
| 123 | ✗ | *got_frame = 1; | |
| 124 | |||
| 125 | ✗ | return pkt->size; | |
| 126 | } | ||
| 127 | |||
| 128 | ✗ | static av_cold int hcom_close(AVCodecContext *avctx) | |
| 129 | { | ||
| 130 | ✗ | HCOMContext *s = avctx->priv_data; | |
| 131 | |||
| 132 | ✗ | av_freep(&s->dict); | |
| 133 | |||
| 134 | ✗ | return 0; | |
| 135 | } | ||
| 136 | |||
| 137 | const FFCodec ff_hcom_decoder = { | ||
| 138 | .p.name = "hcom", | ||
| 139 | CODEC_LONG_NAME("HCOM Audio"), | ||
| 140 | .p.type = AVMEDIA_TYPE_AUDIO, | ||
| 141 | .p.id = AV_CODEC_ID_HCOM, | ||
| 142 | .priv_data_size = sizeof(HCOMContext), | ||
| 143 | .init = hcom_init, | ||
| 144 | .close = hcom_close, | ||
| 145 | FF_CODEC_DECODE_CB(hcom_decode), | ||
| 146 | .p.capabilities = AV_CODEC_CAP_DR1, | ||
| 147 | .caps_internal = FF_CODEC_CAP_INIT_CLEANUP, | ||
| 148 | }; | ||
| 149 |