| 1 | /* |
| 2 | * AST muxer |
| 3 | * Copyright (c) 2012 James Almer |
| 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 "avformat.h" |
| 23 | #include "avio_internal.h" |
| 24 | #include "internal.h" |
| 25 | #include "ast.h" |
| 26 | #include "libavutil/mathematics.h" |
| 27 | #include "libavutil/opt.h" |
| 28 | |
| 29 | typedef struct ASTMuxContext { |
| 30 | AVClass *class; |
| 31 | int64_t size; |
| 32 | int64_t samples; |
| 33 | int64_t loopstart; |
| 34 | int64_t loopend; |
| 35 | int fbs; |
| 36 | } ASTMuxContext; |
| 37 | |
| 38 | #define CHECK_LOOP(type) \ |
| 39 | if (ast->loop ## type > 0) { \ |
| 40 | ast->loop ## type = av_rescale_rnd(ast->loop ## type, enc->sample_rate, 1000, AV_ROUND_DOWN); \ |
| 41 | if (ast->loop ## type < 0 || ast->loop ## type > UINT_MAX) { \ |
| 42 | av_log(s, AV_LOG_ERROR, "Invalid loop" #type " value\n"); \ |
| 43 | return AVERROR(EINVAL); \ |
| 44 | } \ |
| 45 | } |
| 46 | |
| 47 | static int ast_write_header(AVFormatContext *s) |
| 48 | { |
| 49 | ASTMuxContext *ast = s->priv_data; |
| 50 | AVIOContext *pb = s->pb; |
| 51 | AVCodecContext *enc; |
| 52 | unsigned int codec_tag; |
| 53 | |
| 54 | if (s->nb_streams == 1) { |
| 55 | enc = s->streams[0]->codec; |
| 56 | } else { |
| 57 | av_log(s, AV_LOG_ERROR, "only one stream is supported\n"); |
| 58 | return AVERROR(EINVAL); |
| 59 | } |
| 60 | |
| 61 | if (enc->codec_id == AV_CODEC_ID_ADPCM_AFC) { |
| 62 | av_log(s, AV_LOG_ERROR, "muxing ADPCM AFC is not implemented\n"); |
| 63 | return AVERROR_PATCHWELCOME; |
| 64 | } |
| 65 | |
| 66 | codec_tag = ff_codec_get_tag(ff_codec_ast_tags, enc->codec_id); |
| 67 | if (!codec_tag) { |
| 68 | av_log(s, AV_LOG_ERROR, "unsupported codec\n"); |
| 69 | return AVERROR(EINVAL); |
| 70 | } |
| 71 | |
| 72 | if (ast->loopend > 0 && ast->loopstart >= ast->loopend) { |
| 73 | av_log(s, AV_LOG_ERROR, "loopend can't be less or equal to loopstart\n"); |
| 74 | return AVERROR(EINVAL); |
| 75 | } |
| 76 | |
| 77 | /* Convert milliseconds to samples */ |
| 78 | CHECK_LOOP(start) |
| 79 | CHECK_LOOP(end) |
| 80 | |
| 81 | ffio_wfourcc(pb, "STRM"); |
| 82 | |
| 83 | ast->size = avio_tell(pb); |
| 84 | avio_wb32(pb, 0); /* File size minus header */ |
| 85 | avio_wb16(pb, codec_tag); |
| 86 | avio_wb16(pb, 16); /* Bit depth */ |
| 87 | avio_wb16(pb, enc->channels); |
| 88 | avio_wb16(pb, 0); /* Loop flag */ |
| 89 | avio_wb32(pb, enc->sample_rate); |
| 90 | |
| 91 | ast->samples = avio_tell(pb); |
| 92 | avio_wb32(pb, 0); /* Number of samples */ |
| 93 | avio_wb32(pb, 0); /* Loopstart */ |
| 94 | avio_wb32(pb, 0); /* Loopend */ |
| 95 | avio_wb32(pb, 0); /* Size of first block */ |
| 96 | |
| 97 | /* Unknown */ |
| 98 | avio_wb32(pb, 0); |
| 99 | avio_wl32(pb, 0x7F); |
| 100 | avio_wb64(pb, 0); |
| 101 | avio_wb64(pb, 0); |
| 102 | avio_wb32(pb, 0); |
| 103 | |
| 104 | avio_flush(pb); |
| 105 | |
| 106 | return 0; |
| 107 | } |
| 108 | |
| 109 | static int ast_write_packet(AVFormatContext *s, AVPacket *pkt) |
| 110 | { |
| 111 | AVIOContext *pb = s->pb; |
| 112 | ASTMuxContext *ast = s->priv_data; |
| 113 | AVCodecContext *enc = s->streams[0]->codec; |
| 114 | int size = pkt->size / enc->channels; |
| 115 | |
| 116 | if (s->streams[0]->nb_frames == 0) |
| 117 | ast->fbs = size; |
| 118 | |
| 119 | ffio_wfourcc(pb, "BLCK"); |
| 120 | avio_wb32(pb, size); /* Block size */ |
| 121 | |
| 122 | /* padding */ |
| 123 | avio_wb64(pb, 0); |
| 124 | avio_wb64(pb, 0); |
| 125 | avio_wb64(pb, 0); |
| 126 | |
| 127 | avio_write(pb, pkt->data, pkt->size); |
| 128 | |
| 129 | return 0; |
| 130 | } |
| 131 | |
| 132 | static int ast_write_trailer(AVFormatContext *s) |
| 133 | { |
| 134 | AVIOContext *pb = s->pb; |
| 135 | ASTMuxContext *ast = s->priv_data; |
| 136 | AVCodecContext *enc = s->streams[0]->codec; |
| 137 | int64_t file_size = avio_tell(pb); |
| 138 | int64_t samples = (file_size - 64 - (32 * s->streams[0]->nb_frames)) / enc->block_align; /* PCM_S16BE_PLANAR */ |
| 139 | |
| 140 | av_log(s, AV_LOG_DEBUG, "total samples: %"PRId64"\n", samples); |
| 141 | |
| 142 | if (s->pb->seekable) { |
| 143 | /* Number of samples */ |
| 144 | avio_seek(pb, ast->samples, SEEK_SET); |
| 145 | avio_wb32(pb, samples); |
| 146 | |
| 147 | /* Loopstart if provided */ |
| 148 | if (ast->loopstart > 0) { |
| 149 | if (ast->loopstart >= samples) { |
| 150 | av_log(s, AV_LOG_WARNING, "Loopstart value is out of range and will be ignored\n"); |
| 151 | ast->loopstart = -1; |
| 152 | avio_skip(pb, 4); |
| 153 | } else |
| 154 | avio_wb32(pb, ast->loopstart); |
| 155 | } else |
| 156 | avio_skip(pb, 4); |
| 157 | |
| 158 | /* Loopend if provided. Otherwise number of samples again */ |
| 159 | if (ast->loopend && ast->loopstart >= 0) { |
| 160 | if (ast->loopend > samples) { |
| 161 | av_log(s, AV_LOG_WARNING, "Loopend value is out of range and will be ignored\n"); |
| 162 | ast->loopend = samples; |
| 163 | } |
| 164 | avio_wb32(pb, ast->loopend); |
| 165 | } else { |
| 166 | avio_wb32(pb, samples); |
| 167 | } |
| 168 | |
| 169 | /* Size of first block */ |
| 170 | avio_wb32(pb, ast->fbs); |
| 171 | |
| 172 | /* File size minus header */ |
| 173 | avio_seek(pb, ast->size, SEEK_SET); |
| 174 | avio_wb32(pb, file_size - 64); |
| 175 | |
| 176 | /* Loop flag */ |
| 177 | if (ast->loopstart >= 0) { |
| 178 | avio_skip(pb, 6); |
| 179 | avio_wb16(pb, 0xFFFF); |
| 180 | } |
| 181 | |
| 182 | avio_seek(pb, file_size, SEEK_SET); |
| 183 | avio_flush(pb); |
| 184 | } |
| 185 | return 0; |
| 186 | } |
| 187 | |
| 188 | #define OFFSET(obj) offsetof(ASTMuxContext, obj) |
| 189 | static const AVOption options[] = { |
| 190 | { "loopstart", "Loopstart position in milliseconds.", OFFSET(loopstart), AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM }, |
| 191 | { "loopend", "Loopend position in milliseconds.", OFFSET(loopend), AV_OPT_TYPE_INT64, { .i64 = 0 }, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM }, |
| 192 | { NULL }, |
| 193 | }; |
| 194 | |
| 195 | static const AVClass ast_muxer_class = { |
| 196 | .class_name = "AST muxer", |
| 197 | .item_name = av_default_item_name, |
| 198 | .option = options, |
| 199 | .version = LIBAVUTIL_VERSION_INT, |
| 200 | }; |
| 201 | |
| 202 | AVOutputFormat ff_ast_muxer = { |
| 203 | .name = "ast", |
| 204 | .long_name = NULL_IF_CONFIG_SMALL("AST (Audio Stream)"), |
| 205 | .extensions = "ast", |
| 206 | .priv_data_size = sizeof(ASTMuxContext), |
| 207 | .audio_codec = AV_CODEC_ID_PCM_S16BE_PLANAR, |
| 208 | .video_codec = AV_CODEC_ID_NONE, |
| 209 | .write_header = ast_write_header, |
| 210 | .write_packet = ast_write_packet, |
| 211 | .write_trailer = ast_write_trailer, |
| 212 | .priv_class = &ast_muxer_class, |
| 213 | .codec_tag = (const AVCodecTag* const []){ff_codec_ast_tags, 0}, |
| 214 | }; |