/* * id Quake II CIN File Demuxer * Copyright (c) 2003 The FFmpeg project * * 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 */ /** * @file * id Quake II CIN file demuxer by Mike Melanson (melanson@pcisys.net) * For more information about the id CIN format, visit: *   http://www.csse.monash.edu.au/~timf/ * * CIN is a somewhat quirky and ill-defined format. Here are some notes * for anyone trying to understand the technical details of this format: * * The format has no definite file signature. This is problematic for a * general-purpose media player that wants to automatically detect file * types. However, a CIN file does start with 5 32-bit numbers that * specify audio and video parameters. This demuxer gets around the lack * of file signature by performing sanity checks on those parameters. * Probabilistically, this is a reasonable solution since the number of * valid combinations of the 5 parameters is a very small subset of the * total 160-bit number space. * * Refer to the function idcin_probe() for the precise A/V parameters * that this demuxer allows. * * Next, each audio and video frame has a duration of 1/14 sec. If the * audio sample rate is a multiple of the common frequency 22050 Hz it will * divide evenly by 14. However, if the sample rate is 11025 Hz: *   11025 (samples/sec) / 14 (frames/sec) = 787.5 (samples/frame) * The way the CIN stores audio in this case is by storing 787 sample * frames in the first audio frame and 788 sample frames in the second * audio frame. Therefore, the total number of bytes in an audio frame * is given as: *   audio frame #0: 787 * (bytes/sample) * (# channels) bytes in frame *   audio frame #1: 788 * (bytes/sample) * (# channels) bytes in frame *   audio frame #2: 787 * (bytes/sample) * (# channels) bytes in frame *   audio frame #3: 788 * (bytes/sample) * (# channels) bytes in frame * * Finally, not all id CIN creation tools agree on the resolution of the * color palette, apparently. Some creation tools specify red, green, and * blue palette components in terms of 6-bit VGA color DAC values which * range from 0..63. Other tools specify the RGB components as full 8-bit * values that range from 0..255. Since there are no markers in the file to * differentiate between the two variants, this demuxer uses the following * heuristic: *   - load the 768 palette bytes from disk *   - assume that they will need to be shifted left by 2 bits to *     transform them from 6-bit values to 8-bit values *   - scan through all 768 palette bytes *     - if any bytes exceed 63, do not shift the bytes at all before *       transmitting them to the video decoder */ #include "libavutil/channel_layout.h"#include "libavutil/imgutils.h"#include "libavutil/intreadwrite.h"#include "avformat.h"#include "internal.h" #define HUFFMAN_TABLE_SIZE (64 * 1024)#define IDCIN_FPS 14 typedef struct IdcinDemuxContext {    int video_stream_index;    int audio_stream_index;    int audio_chunk_size1;    int audio_chunk_size2;    int block_align;     /* demux state variables */    int current_audio_chunk;    int next_chunk_is_video;    int audio_present;    int64_t first_pkt_pos;} IdcinDemuxContext; static int idcin_probe(AVProbeData *p){    unsigned int number, sample_rate;    unsigned int w, h;    int i;     /*     * This is what you could call a "probabilistic" file check: id CIN     * files don't have a definite file signature. In lieu of such a marker,     * perform sanity checks on the 5 32-bit header fields:     *  width, height: greater than 0, less than or equal to 1024     * audio sample rate: greater than or equal to 8000, less than or     *  equal to 48000, or 0 for no audio     * audio sample width (bytes/sample): 0 for no audio, or 1 or 2     * audio channels: 0 for no audio, or 1 or 2     */     /* check we have enough data to do all checks, otherwise the       0-padding may cause a wrong recognition */    if (p->buf_size < 20 + HUFFMAN_TABLE_SIZE + 12)        return 0;     /* check the video width */    w = AV_RL32(&p->buf[0]);    if ((w == 0) || (w > 1024))       return 0;     /* check the video height */    h = AV_RL32(&p->buf[4]);    if ((h == 0) || (h > 1024))       return 0;     /* check the audio sample rate */    sample_rate = AV_RL32(&p->buf[8]);    if (sample_rate && (sample_rate < 8000 || sample_rate > 48000))        return 0;     /* check the audio bytes/sample */    number = AV_RL32(&p->buf[12]);    if (number > 2 || sample_rate && !number)        return 0;     /* check the audio channels */    number = AV_RL32(&p->buf[16]);    if (number > 2 || sample_rate && !number)        return 0;     i = 20 + HUFFMAN_TABLE_SIZE;    if (AV_RL32(&p->buf[i]) == 1)        i += 768;     if (i+12 > p->buf_size || AV_RL32(&p->buf[i+8]) != w*h)        return 1;     /* return half certainty since this check is a bit sketchy */    return AVPROBE_SCORE_EXTENSION;} static int idcin_read_header(AVFormatContext *s){    AVIOContext *pb = s->pb;    IdcinDemuxContext *idcin = s->priv_data;    AVStream *st;    unsigned int width, height;    unsigned int sample_rate, bytes_per_sample, channels;    int ret;     /* get the 5 header parameters */    width = avio_rl32(pb);    height = avio_rl32(pb);    sample_rate = avio_rl32(pb);    bytes_per_sample = avio_rl32(pb);    channels = avio_rl32(pb);     if (s->pb->eof_reached) {        av_log(s, AV_LOG_ERROR, "incomplete header\n");        return s->pb->error ? s->pb->error : AVERROR_EOF;    }     if (av_image_check_size(width, height, 0, s) < 0)        return AVERROR_INVALIDDATA;    if (sample_rate > 0) {        if (sample_rate < 14 || sample_rate > INT_MAX) {            av_log(s, AV_LOG_ERROR, "invalid sample rate: %u\n", sample_rate);            return AVERROR_INVALIDDATA;        }        if (bytes_per_sample < 1 || bytes_per_sample > 2) {            av_log(s, AV_LOG_ERROR, "invalid bytes per sample: %u\n",                   bytes_per_sample);            return AVERROR_INVALIDDATA;        }        if (channels < 1 || channels > 2) {            av_log(s, AV_LOG_ERROR, "invalid channels: %u\n", channels);            return AVERROR_INVALIDDATA;        }        idcin->audio_present = 1;    } else {        /* if sample rate is 0, assume no audio */        idcin->audio_present = 0;    }     st = avformat_new_stream(s, NULL);    if (!st)        return AVERROR(ENOMEM);    avpriv_set_pts_info(st, 33, 1, IDCIN_FPS);    st->start_time = 0;    idcin->video_stream_index = st->index;    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;    st->codecpar->codec_id = AV_CODEC_ID_IDCIN;    st->codecpar->codec_tag = 0;  /* no fourcc */    st->codecpar->width = width;    st->codecpar->height = height;     /* load up the Huffman tables into extradata */    if ((ret = ff_get_extradata(s, st->codecpar, pb, HUFFMAN_TABLE_SIZE)) < 0)        return ret;     if (idcin->audio_present) {        idcin->audio_present = 1;        st = avformat_new_stream(s, NULL);        if (!st)            return AVERROR(ENOMEM);        avpriv_set_pts_info(st, 63, 1, sample_rate);        st->start_time = 0;        idcin->audio_stream_index = st->index;        st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;        st->codecpar->codec_tag = 1;        st->codecpar->channels = channels;        st->codecpar->channel_layout = channels > 1 ? AV_CH_LAYOUT_STEREO :                                                      AV_CH_LAYOUT_MONO;        st->codecpar->sample_rate = sample_rate;        st->codecpar->bits_per_coded_sample = bytes_per_sample * 8;        st->codecpar->bit_rate = sample_rate * bytes_per_sample * 8 * channels;        st->codecpar->block_align = idcin->block_align = bytes_per_sample * channels;        if (bytes_per_sample == 1)            st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;        else            st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE;         if (sample_rate % 14 != 0) {            idcin->audio_chunk_size1 = (sample_rate / 14) *            bytes_per_sample * channels;            idcin->audio_chunk_size2 = (sample_rate / 14 + 1) *                bytes_per_sample * channels;        } else {            idcin->audio_chunk_size1 = idcin->audio_chunk_size2 =                (sample_rate / 14) * bytes_per_sample * channels;        }        idcin->current_audio_chunk = 0;    }     idcin->next_chunk_is_video = 1;    idcin->first_pkt_pos = avio_tell(s->pb);     return 0;} static int idcin_read_packet(AVFormatContext *s,                             AVPacket *pkt){    int ret;    unsigned int command;    unsigned int chunk_size;    IdcinDemuxContext *idcin = s->priv_data;    AVIOContext *pb = s->pb;    int i;    int palette_scale;    unsigned char r, g, b;    unsigned char palette_buffer[768];    uint32_t palette[256];     if (avio_feof(s->pb))        return s->pb->error ? s->pb->error : AVERROR_EOF;     if (idcin->next_chunk_is_video) {        command = avio_rl32(pb);        if (command == 2) {            return AVERROR(EIO);        } else if (command == 1) {            /* trigger a palette change */            ret = avio_read(pb, palette_buffer, 768);            if (ret < 0) {                return ret;            } else if (ret != 768) {                av_log(s, AV_LOG_ERROR, "incomplete packet\n");                return AVERROR(EIO);            }            /* scale the palette as necessary */            palette_scale = 2;            for (i = 0; i < 768; i++)                if (palette_buffer[i] > 63) {                    palette_scale = 0;                    break;                }             for (i = 0; i < 256; i++) {                r = palette_buffer[i * 3    ] << palette_scale;                g = palette_buffer[i * 3 + 1] << palette_scale;                b = palette_buffer[i * 3 + 2] << palette_scale;                palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | (b);                if (palette_scale == 2)                    palette[i] |= palette[i] >> 6 & 0x30303;            }        }         if (s->pb->eof_reached) {            av_log(s, AV_LOG_ERROR, "incomplete packet\n");            return s->pb->error ? s->pb->error : AVERROR_EOF;        }        chunk_size = avio_rl32(pb);        if (chunk_size < 4 || chunk_size > INT_MAX - 4) {            av_log(s, AV_LOG_ERROR, "invalid chunk size: %u\n", chunk_size);            return AVERROR_INVALIDDATA;        }        /* skip the number of decoded bytes (always equal to width * height) */        avio_skip(pb, 4);        chunk_size -= 4;        ret= av_get_packet(pb, pkt, chunk_size);        if (ret < 0)            return ret;        else if (ret != chunk_size) {            av_log(s, AV_LOG_ERROR, "incomplete packet\n");            av_packet_unref(pkt);            return AVERROR(EIO);        }        if (command == 1) {            uint8_t *pal;             pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE,                                          AVPALETTE_SIZE);            if (!pal) {                av_packet_unref(pkt);                return AVERROR(ENOMEM);            }            memcpy(pal, palette, AVPALETTE_SIZE);            pkt->flags |= AV_PKT_FLAG_KEY;        }        pkt->stream_index = idcin->video_stream_index;        pkt->duration     = 1;    } else {        /* send out the audio chunk */        if (idcin->current_audio_chunk)            chunk_size = idcin->audio_chunk_size2;        else            chunk_size = idcin->audio_chunk_size1;        ret= av_get_packet(pb, pkt, chunk_size);        if (ret < 0)            return ret;        pkt->stream_index = idcin->audio_stream_index;        pkt->duration     = chunk_size / idcin->block_align;         idcin->current_audio_chunk ^= 1;    }     if (idcin->audio_present)        idcin->next_chunk_is_video ^= 1;     return 0;} static int idcin_read_seek(AVFormatContext *s, int stream_index,                           int64_t timestamp, int flags){    IdcinDemuxContext *idcin = s->priv_data;     if (idcin->first_pkt_pos > 0) {        int64_t ret = avio_seek(s->pb, idcin->first_pkt_pos, SEEK_SET);        if (ret < 0)            return ret;        ff_update_cur_dts(s, s->streams[idcin->video_stream_index], 0);        idcin->next_chunk_is_video = 1;        idcin->current_audio_chunk = 0;        return 0;    }    return -1;} AVInputFormat ff_idcin_demuxer = {    .name           = "idcin",    .long_name      = NULL_IF_CONFIG_SMALL("id Cinematic"),    .priv_data_size = sizeof(IdcinDemuxContext),    .read_probe     = idcin_probe,    .read_header    = idcin_read_header,    .read_packet    = idcin_read_packet,    .read_seek      = idcin_read_seek,    .flags          = AVFMT_NO_BYTE_SEEK,};