yading@11: /*
yading@11:  * AST muxer
yading@11:  * Copyright (c) 2012 James Almer
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "avformat.h"
yading@11: #include "avio_internal.h"
yading@11: #include "internal.h"
yading@11: #include "ast.h"
yading@11: #include "libavutil/mathematics.h"
yading@11: #include "libavutil/opt.h"
yading@11: 
yading@11: typedef struct ASTMuxContext {
yading@11:     AVClass *class;
yading@11:     int64_t  size;
yading@11:     int64_t  samples;
yading@11:     int64_t  loopstart;
yading@11:     int64_t  loopend;
yading@11:     int      fbs;
yading@11: } ASTMuxContext;
yading@11: 
yading@11: #define CHECK_LOOP(type) \
yading@11:     if (ast->loop ## type > 0) { \
yading@11:         ast->loop ## type = av_rescale_rnd(ast->loop ## type, enc->sample_rate, 1000, AV_ROUND_DOWN); \
yading@11:         if (ast->loop ## type < 0 || ast->loop ## type > UINT_MAX) { \
yading@11:             av_log(s, AV_LOG_ERROR, "Invalid loop" #type " value\n"); \
yading@11:             return AVERROR(EINVAL);  \
yading@11:         } \
yading@11:     }
yading@11: 
yading@11: static int ast_write_header(AVFormatContext *s)
yading@11: {
yading@11:     ASTMuxContext *ast = s->priv_data;
yading@11:     AVIOContext *pb = s->pb;
yading@11:     AVCodecContext *enc;
yading@11:     unsigned int codec_tag;
yading@11: 
yading@11:     if (s->nb_streams == 1) {
yading@11:         enc = s->streams[0]->codec;
yading@11:     } else {
yading@11:         av_log(s, AV_LOG_ERROR, "only one stream is supported\n");
yading@11:         return AVERROR(EINVAL);
yading@11:     }
yading@11: 
yading@11:     if (enc->codec_id == AV_CODEC_ID_ADPCM_AFC) {
yading@11:         av_log(s, AV_LOG_ERROR, "muxing ADPCM AFC is not implemented\n");
yading@11:         return AVERROR_PATCHWELCOME;
yading@11:     }
yading@11: 
yading@11:     codec_tag = ff_codec_get_tag(ff_codec_ast_tags, enc->codec_id);
yading@11:     if (!codec_tag) {
yading@11:         av_log(s, AV_LOG_ERROR, "unsupported codec\n");
yading@11:         return AVERROR(EINVAL);
yading@11:     }
yading@11: 
yading@11:     if (ast->loopend > 0 && ast->loopstart >= ast->loopend) {
yading@11:         av_log(s, AV_LOG_ERROR, "loopend can't be less or equal to loopstart\n");
yading@11:         return AVERROR(EINVAL);
yading@11:     }
yading@11: 
yading@11:     /* Convert milliseconds to samples */
yading@11:     CHECK_LOOP(start)
yading@11:     CHECK_LOOP(end)
yading@11: 
yading@11:     ffio_wfourcc(pb, "STRM");
yading@11: 
yading@11:     ast->size = avio_tell(pb);
yading@11:     avio_wb32(pb, 0); /* File size minus header */
yading@11:     avio_wb16(pb, codec_tag);
yading@11:     avio_wb16(pb, 16); /* Bit depth */
yading@11:     avio_wb16(pb, enc->channels);
yading@11:     avio_wb16(pb, 0); /* Loop flag */
yading@11:     avio_wb32(pb, enc->sample_rate);
yading@11: 
yading@11:     ast->samples = avio_tell(pb);
yading@11:     avio_wb32(pb, 0); /* Number of samples */
yading@11:     avio_wb32(pb, 0); /* Loopstart */
yading@11:     avio_wb32(pb, 0); /* Loopend */
yading@11:     avio_wb32(pb, 0); /* Size of first block */
yading@11: 
yading@11:     /* Unknown */
yading@11:     avio_wb32(pb, 0);
yading@11:     avio_wl32(pb, 0x7F);
yading@11:     avio_wb64(pb, 0);
yading@11:     avio_wb64(pb, 0);
yading@11:     avio_wb32(pb, 0);
yading@11: 
yading@11:     avio_flush(pb);
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int ast_write_packet(AVFormatContext *s, AVPacket *pkt)
yading@11: {
yading@11:     AVIOContext *pb = s->pb;
yading@11:     ASTMuxContext *ast = s->priv_data;
yading@11:     AVCodecContext *enc = s->streams[0]->codec;
yading@11:     int size = pkt->size / enc->channels;
yading@11: 
yading@11:     if (enc->frame_number == 1)
yading@11:         ast->fbs = size;
yading@11: 
yading@11:     ffio_wfourcc(pb, "BLCK");
yading@11:     avio_wb32(pb, size); /* Block size */
yading@11: 
yading@11:     /* padding */
yading@11:     avio_wb64(pb, 0);
yading@11:     avio_wb64(pb, 0);
yading@11:     avio_wb64(pb, 0);
yading@11: 
yading@11:     avio_write(pb, pkt->data, pkt->size);
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int ast_write_trailer(AVFormatContext *s)
yading@11: {
yading@11:     AVIOContext *pb = s->pb;
yading@11:     ASTMuxContext *ast = s->priv_data;
yading@11:     AVCodecContext *enc = s->streams[0]->codec;
yading@11:     int64_t file_size = avio_tell(pb);
yading@11:     int64_t samples = (file_size - 64 - (32 * enc->frame_number)) / enc->block_align; /* PCM_S16BE_PLANAR */
yading@11: 
yading@11:     av_log(s, AV_LOG_DEBUG, "total samples: %"PRId64"\n", samples);
yading@11: 
yading@11:     if (s->pb->seekable) {
yading@11:         /* Number of samples */
yading@11:         avio_seek(pb, ast->samples, SEEK_SET);
yading@11:         avio_wb32(pb, samples);
yading@11: 
yading@11:         /* Loopstart if provided */
yading@11:         if (ast->loopstart > 0) {
yading@11:         if (ast->loopstart >= samples) {
yading@11:             av_log(s, AV_LOG_WARNING, "Loopstart value is out of range and will be ignored\n");
yading@11:             ast->loopstart = -1;
yading@11:             avio_skip(pb, 4);
yading@11:         } else
yading@11:         avio_wb32(pb, ast->loopstart);
yading@11:         } else
yading@11:             avio_skip(pb, 4);
yading@11: 
yading@11:         /* Loopend if provided. Otherwise number of samples again */
yading@11:         if (ast->loopend && ast->loopstart >= 0) {
yading@11:             if (ast->loopend > samples) {
yading@11:                 av_log(s, AV_LOG_WARNING, "Loopend value is out of range and will be ignored\n");
yading@11:                 ast->loopend = samples;
yading@11:             }
yading@11:             avio_wb32(pb, ast->loopend);
yading@11:         } else {
yading@11:             avio_wb32(pb, samples);
yading@11:         }
yading@11: 
yading@11:         /* Size of first block */
yading@11:         avio_wb32(pb, ast->fbs);
yading@11: 
yading@11:         /* File size minus header */
yading@11:         avio_seek(pb, ast->size, SEEK_SET);
yading@11:         avio_wb32(pb, file_size - 64);
yading@11: 
yading@11:         /* Loop flag */
yading@11:         if (ast->loopstart >= 0) {
yading@11:             avio_skip(pb, 6);
yading@11:             avio_wb16(pb, 0xFFFF);
yading@11:         }
yading@11: 
yading@11:         avio_seek(pb, file_size, SEEK_SET);
yading@11:         avio_flush(pb);
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: #define OFFSET(obj) offsetof(ASTMuxContext, obj)
yading@11: static const AVOption options[] = {
yading@11:   { "loopstart", "Loopstart position in milliseconds.", OFFSET(loopstart), AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
yading@11:   { "loopend",   "Loopend position in milliseconds.",   OFFSET(loopend),   AV_OPT_TYPE_INT64, { .i64 = 0 }, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
yading@11:   { NULL },
yading@11: };
yading@11: 
yading@11: static const AVClass ast_muxer_class = {
yading@11:     .class_name = "AST muxer",
yading@11:     .item_name  = av_default_item_name,
yading@11:     .option     = options,
yading@11:     .version    = LIBAVUTIL_VERSION_INT,
yading@11: };
yading@11: 
yading@11: AVOutputFormat ff_ast_muxer = {
yading@11:     .name              = "ast",
yading@11:     .long_name         = NULL_IF_CONFIG_SMALL("AST (Audio Stream)"),
yading@11:     .extensions        = "ast",
yading@11:     .priv_data_size    = sizeof(ASTMuxContext),
yading@11:     .audio_codec       = AV_CODEC_ID_PCM_S16BE_PLANAR,
yading@11:     .video_codec       = AV_CODEC_ID_NONE,
yading@11:     .write_header      = ast_write_header,
yading@11:     .write_packet      = ast_write_packet,
yading@11:     .write_trailer     = ast_write_trailer,
yading@11:     .priv_class        = &ast_muxer_class,
yading@11:     .codec_tag         = (const AVCodecTag* const []){ff_codec_ast_tags, 0},
yading@11: };