/* * Interplay C93 demuxer * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com> * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "avformat.h"#include "demux.h"#include "internal.h"#include "voc.h"#include "libavutil/intreadwrite.h" typedef struct C93BlockRecord {    uint16_t index;    uint8_t length;    uint8_t frames;} C93BlockRecord; typedef struct C93DemuxContext {    VocDecContext voc;     C93BlockRecord block_records[512];    int current_block;     uint32_t frame_offsets[32];    int current_frame;    int next_pkt_is_audio;     AVStream *audio;} C93DemuxContext; static int probe(const AVProbeData *p){    int i;    int index = 1;    if (p->buf_size < 16)        return 0;    for (i = 0; i < 16; i += 4) {        if (AV_RL16(p->buf + i) != index || !p->buf[i + 2] || !p->buf[i + 3])            return 0;        index += p->buf[i + 2];    }    return AVPROBE_SCORE_MAX;} static int read_header(AVFormatContext *s){    AVStream *video;    AVIOContext *pb = s->pb;    C93DemuxContext *c93 = s->priv_data;    int i;    int framecount = 0;     for (i = 0; i < 512; i++) {        c93->block_records[i].index = avio_rl16(pb);        c93->block_records[i].length = avio_r8(pb);        c93->block_records[i].frames = avio_r8(pb);        if (c93->block_records[i].frames > 32) {            av_log(s, AV_LOG_ERROR, "too many frames in block\n");            return AVERROR_INVALIDDATA;        }        framecount += c93->block_records[i].frames;    }     /* Audio streams are added if audio packets are found */    s->ctx_flags |= AVFMTCTX_NOHEADER;     video = avformat_new_stream(s, NULL);    if (!video)        return AVERROR(ENOMEM);     video->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;    video->codecpar->codec_id = AV_CODEC_ID_C93;    video->codecpar->width = 320;    video->codecpar->height = 192;    /* 4:3 320x200 with 8 empty lines */    video->sample_aspect_ratio = (AVRational) { 5, 6 };    avpriv_set_pts_info(video, 64, 2, 25);    video->nb_frames = framecount;    video->duration = framecount;    video->start_time = 0;     c93->current_block = 0;    c93->current_frame = 0;    c93->next_pkt_is_audio = 0;    return 0;} #define C93_HAS_PALETTE 0x01#define C93_FIRST_FRAME 0x02 static int read_packet(AVFormatContext *s, AVPacket *pkt){    AVIOContext *pb = s->pb;    C93DemuxContext *c93 = s->priv_data;    C93BlockRecord *br = &c93->block_records[c93->current_block];    int datasize;    int ret, i;     if (c93->next_pkt_is_audio) {        c93->current_frame++;        c93->next_pkt_is_audio = 0;        datasize = avio_rl16(pb);        if (datasize > 42) {            if (!c93->audio) {                c93->audio = avformat_new_stream(s, NULL);                if (!c93->audio)                    return AVERROR(ENOMEM);                c93->audio->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;            }            avio_skip(pb, 26); /* VOC header */            ret = ff_voc_get_packet(s, pkt, c93->audio, datasize - 26);            if (ret > 0) {                pkt->stream_index = 1;                pkt->flags |= AV_PKT_FLAG_KEY;                return ret;            }        }    }    if (c93->current_frame >= br->frames) {        if (c93->current_block >= 511 || !br[1].length)            return AVERROR_EOF;        br++;        c93->current_block++;        c93->current_frame = 0;    }     if (c93->current_frame == 0) {        avio_seek(pb, br->index * 2048, SEEK_SET);        for (i = 0; i < 32; i++) {            c93->frame_offsets[i] = avio_rl32(pb);        }    }     avio_seek(pb,br->index * 2048 +            c93->frame_offsets[c93->current_frame], SEEK_SET);    datasize = avio_rl16(pb); /* video frame size */     ret = av_new_packet(pkt, datasize + 768 + 1);    if (ret < 0)        return ret;    pkt->data[0] = 0;    pkt->size = datasize + 1;     ret = avio_read(pb, pkt->data + 1, datasize);    if (ret < datasize) {        return AVERROR(EIO);    }     datasize = avio_rl16(pb); /* palette size */    if (datasize) {        if (datasize != 768) {            av_log(s, AV_LOG_ERROR, "invalid palette size %u\n", datasize);            return AVERROR_INVALIDDATA;        }        pkt->data[0] |= C93_HAS_PALETTE;        ret = avio_read(pb, pkt->data + pkt->size, datasize);        if (ret < datasize) {            return AVERROR(EIO);        }        pkt->size += 768;    }    pkt->stream_index = 0;    c93->next_pkt_is_audio = 1;     /* only the first frame is guaranteed to not reference previous frames */    if (c93->current_block == 0 && c93->current_frame == 0) {        pkt->flags |= AV_PKT_FLAG_KEY;        pkt->data[0] |= C93_FIRST_FRAME;    }    return 0;} const FFInputFormat ff_c93_demuxer = {    .p.name         = "c93",    .p.long_name    = NULL_IF_CONFIG_SMALL("Interplay C93"),    .priv_data_size = sizeof(C93DemuxContext),    .read_probe     = probe,    .read_header    = read_header,    .read_packet    = read_packet,};