libavformat/astenc.c

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