[FFmpeg-devel] [PATCH] avformat/scd: add demuxer

Zane van Iperen zane at zanevaniperen.com
Fri Nov 12 20:22:39 EET 2021


Ping?

Pretty sure most people didn't get this as I was making DMARC changes at the time. I can re-send if necessary.

On 4/11/21 00:29, Zane van Iperen wrote:
> Adds demuxer for Square Enux SCD files.
> 

s/Enux/Enix/

> Based off [1] and personal investigation.
> 
> This has only been tested against Drakengard 3 (PS3) *_SCD.XXX files
> (big-endian). As it is highly likely that FFXIV (PC) files are little-endian,
> this demuxer is marked as experimental until this can be confirmed.
> 
> [1]: http://ffxivexplorer.fragmenterworks.com/research/scd%20files.txt
> 
> Signed-off-by: Zane van Iperen <zane at zanevaniperen.com>
> ---
>   libavformat/Makefile     |   1 +
>   libavformat/allformats.c |   1 +
>   libavformat/scd.c        | 377 +++++++++++++++++++++++++++++++++++++++
>   3 files changed, 379 insertions(+)
>   create mode 100644 libavformat/scd.c
> 
> diff --git a/libavformat/Makefile b/libavformat/Makefile
> index 3d6c8ef8f5..725e8c0ed6 100644
> --- a/libavformat/Makefile
> +++ b/libavformat/Makefile
> @@ -500,6 +500,7 @@ OBJS-$(CONFIG_SBC_MUXER)                 += rawenc.o
>   OBJS-$(CONFIG_SBG_DEMUXER)               += sbgdec.o
>   OBJS-$(CONFIG_SCC_DEMUXER)               += sccdec.o subtitles.o
>   OBJS-$(CONFIG_SCC_MUXER)                 += sccenc.o subtitles.o
> +OBJS-$(CONFIG_SCD_DEMUXER)               += scd.o
>   OBJS-$(CONFIG_SDP_DEMUXER)               += rtsp.o
>   OBJS-$(CONFIG_SDR2_DEMUXER)              += sdr2.o
>   OBJS-$(CONFIG_SDS_DEMUXER)               += sdsdec.o
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index cbfadcb639..1054ac9667 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -392,6 +392,7 @@ extern const AVOutputFormat ff_sbc_muxer;
>   extern const AVInputFormat  ff_sbg_demuxer;
>   extern const AVInputFormat  ff_scc_demuxer;
>   extern const AVOutputFormat ff_scc_muxer;
> +extern const AVInputFormat  ff_scd_demuxer;
>   extern const AVInputFormat  ff_sdp_demuxer;
>   extern const AVInputFormat  ff_sdr2_demuxer;
>   extern const AVInputFormat  ff_sds_demuxer;
> diff --git a/libavformat/scd.c b/libavformat/scd.c
> new file mode 100644
> index 0000000000..5bb01d2114
> --- /dev/null
> +++ b/libavformat/scd.c
> @@ -0,0 +1,377 @@
> +/*
> + * Square Enix SCD demuxer
> + * Copyright (C) 2021 Zane van Iperen (zane at zanevaniperen.com)
> + *
> + * Based off documentation:
> + *   http://ffxivexplorer.fragmenterworks.com/research/scd%20files.txt
> + *
> + * 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 "libavutil/avstring.h"
> +#include "libavutil/intreadwrite.h"
> +#include "libavutil/internal.h"
> +#include "libavutil/macros.h"
> +#include "libavutil/avassert.h"
> +#include "libavformat/internal.h"
> +#include "avformat.h"
> +
> +#define SCD_MAGIC              ((uint64_t)MKBETAG('S', 'E', 'D', 'B') << 32 | \
> +                                          MKBETAG('S', 'S', 'C', 'F'))
> +#define SCD_MIN_HEADER_SIZE    20
> +#define SCD_OFFSET_HEADER_SIZE 28
> +#define SCD_TRACK_HEADER_SIZE  32
> +
> +#define SCD_TRACK_ID_PCM        0
> +#define SCD_TRACK_ID_OGG        6
> +#define SCD_TRACK_ID_MP3        7
> +#define SCD_TRACK_ID_MS_ADPCM  12
> +
> +typedef struct SCDOffsetTable {
> +    uint16_t  count;
> +    uint32_t  offset;
> +    uint32_t *entries;
> +} SCDOffsetTable;
> +
> +typedef struct SCDHeader {
> +    uint64_t magic;         /* SEDBSSCF                                     */
> +    uint32_t version;       /* Verison number. We only know about 3.        */
> +    uint16_t unk1;          /* Unknown, 260 in Drakengard 3, 1024 in FFXIV. */
> +    uint16_t header_size;   /* Total size of this header.                   */
> +    uint32_t file_size;     /* Is often 0, just ignore it.                  */
> +
> +    SCDOffsetTable table0;  /* Table 0, no idea. 56 uint32's/entry.         */
> +    SCDOffsetTable table1;  /* Table 1, contains the track info.            */
> +    SCDOffsetTable table2;  /* Table 2, no idea. 40 uint32's/entry.         */
> +    uint16_t unk2;          /* Unknown, not a count.                        */
> +    uint32_t unk3;          /* Unknown, not an offset.                      */
> +    uint32_t unk4;          /* Unknown, offset to offset.                   */
> +} SCDHeader;
> +
> +typedef struct SCDTrackHeader {
> +    uint32_t length;
> +    uint32_t num_channels;
> +    uint32_t sample_rate;
> +    uint32_t data_type;
> +    uint32_t loop_start;
> +    uint32_t loop_end;
> +    uint32_t data_offset; /* Offset to data + this header. */
> +    uint32_t aux_count;
> +
> +    uint32_t absolute_offset;
> +    uint32_t bytes_read;
> +} SCDTrackHeader;
> +
> +typedef struct SCDDemuxContext {
> +    SCDHeader        hdr;
> +    SCDTrackHeader  *tracks;
> +    int              current_track;
> +} SCDDemuxContext;
> +
> +static int scd_probe(const AVProbeData *p)
> +{
> +    if (AV_RB64(p->buf) != SCD_MAGIC)
> +        return 0;
> +
> +    return AVPROBE_SCORE_MAX;
> +}
> +
> +static int scd_read_table(AVFormatContext *s, SCDOffsetTable *table)
> +{
> +    int64_t ret;
> +
> +    if ((ret = avio_seek(s->pb, table->offset, SEEK_SET)) < 0)
> +        return ret;
> +
> +    if ((table->entries = av_calloc(table->count, sizeof(uint32_t))) == NULL)
> +        return ret;
> +
> +    if ((ret = avio_read(s->pb, (unsigned char*)table->entries, table->count * sizeof(uint32_t))) < 0)
> +        return ret;
> +
> +    for (size_t i = 0; i < table->count; i++)
> +        table->entries[i] = AV_RB32(table->entries + i);
> +
> +    av_log(s, AV_LOG_TRACE, "Table, size = %u, offset = %u\n", table->count, table->offset);
> +    for (size_t i = 0; i < table->count; i++)
> +        av_log(s, AV_LOG_TRACE, "  [%02zu]: %u\n", i, table->entries[i]);
> +
> +    return 0;
> +}
> +
> +static int scd_read_offsets(AVFormatContext *s)
> +{
> +    int64_t ret;
> +    SCDDemuxContext  *ctx = s->priv_data;
> +    uint8_t buf[SCD_OFFSET_HEADER_SIZE];
> +
> +    if ((ret = avio_read(s->pb, buf, SCD_OFFSET_HEADER_SIZE)) < 0)
> +        return ret;
> +
> +    ctx->hdr.table0.count  = AV_RB16(buf +  0);
> +    ctx->hdr.table1.count  = AV_RB16(buf +  2);
> +    ctx->hdr.table2.count  = AV_RB16(buf +  4);
> +    ctx->hdr.unk2          = AV_RB16(buf +  6);
> +    ctx->hdr.table0.offset = AV_RB32(buf +  8);
> +    ctx->hdr.table1.offset = AV_RB32(buf + 12);
> +    ctx->hdr.table2.offset = AV_RB32(buf + 16);
> +    ctx->hdr.unk3          = AV_RB32(buf + 20);
> +    ctx->hdr.unk4          = AV_RB32(buf + 24);
> +
> +    if ((ret = scd_read_table(s, &ctx->hdr.table0)) < 0)
> +        return ret;
> +
> +    if ((ret = scd_read_table(s, &ctx->hdr.table1)) < 0)
> +        return ret;
> +
> +    if ((ret = scd_read_table(s, &ctx->hdr.table2)) < 0)
> +        return ret;
> +
> +    return 0;
> +}
> +
> +static int scd_read_track(AVFormatContext *s, SCDTrackHeader *track, int index)
> +{
> +    int64_t ret;
> +    uint32_t hoffset;
> +    AVStream *st;
> +    AVCodecParameters *par;
> +    SCDDemuxContext *ctx = s->priv_data;
> +    uint8_t buf[SCD_TRACK_HEADER_SIZE];
> +
> +    /* Mark as experimental until I find more files from more than just one game. */
> +    if (s->strict_std_compliance > FF_COMPLIANCE_EXPERIMENTAL) {
> +        av_log(s, AV_LOG_ERROR, "SCD demuxing is experimental, "
> +               "add '-strict %d' if you want to use it.\n",
> +               FF_COMPLIANCE_EXPERIMENTAL);
> +        return AVERROR_EXPERIMENTAL;
> +    }
> +
> +    hoffset = ctx->hdr.table1.entries[index];
> +
> +    if ((ret = avio_seek(s->pb, hoffset, SEEK_SET)) < 0)
> +        return ret;
> +
> +    if ((ret = avio_read(s->pb, buf, SCD_TRACK_HEADER_SIZE)) < 0)
> +        return ret;
> +
> +    track->length       = AV_RB32(buf +  0);
> +    track->num_channels = AV_RB32(buf +  4);
> +    track->sample_rate  = AV_RB32(buf +  8);
> +    track->data_type    = AV_RB32(buf + 12);
> +    track->loop_start   = AV_RB32(buf + 16);
> +    track->loop_end     = AV_RB32(buf + 20);
> +    track->data_offset  = AV_RB32(buf + 24);
> +    track->aux_count    = AV_RB32(buf + 28);
> +
> +    /* Sanity checks */
> +    if (track->num_channels > 8 || track->sample_rate >= 192000 ||
> +        track->loop_start > track->loop_end)
> +        return AVERROR_INVALIDDATA;
> +
> +    track->absolute_offset = hoffset + SCD_TRACK_HEADER_SIZE + track->data_offset;
> +    track->bytes_read      = 0;
> +
> +    /* Not sure what to do with these, it seems to be fine to ignore them. */
> +    if (track->aux_count != 0)
> +        av_log(s, AV_LOG_DEBUG, "[%d] Track has %u auxillary chunk(s).\n", index, track->aux_count);
> +
> +    if ((st = avformat_new_stream(s, NULL)) == NULL)
> +        return AVERROR(ENOMEM);
> +
> +    par               = st->codecpar;
> +    par->codec_type   = AVMEDIA_TYPE_AUDIO;
> +    par->channels     = (int)track->num_channels;
> +    par->sample_rate  = (int)track->sample_rate;
> +    st->index         = index;
> +    st->start_time    = 0;
> +
> +    /* TODO: Check this with other types. Drakengard 3 MP3s have 47999 instead of 48000. */
> +    if (track->data_type == SCD_TRACK_ID_MP3)
> +        par->sample_rate += 1;
> +
> +    avpriv_set_pts_info(st, 64, 1, par->sample_rate);
> +
> +    if (av_dict_set_int(&st->metadata, "start", track->absolute_offset, 0) < 0)
> +        return AVERROR(ENOMEM);
> +
> +    if (av_dict_set_int(&st->metadata, "loop_start", track->loop_start, 0) < 0)
> +        return AVERROR(ENOMEM);
> +
> +    if (av_dict_set_int(&st->metadata, "loop_end", track->loop_end, 0) < 0)
> +        return AVERROR(ENOMEM);
> +
> +    switch(track->data_type) {
> +        case SCD_TRACK_ID_PCM:
> +            par->codec_id              = AV_CODEC_ID_PCM_S16BE;
> +            par->bits_per_coded_sample = 16;
> +            par->block_align           = par->bits_per_coded_sample * par->channels / 8;
> +            break;
> +        case SCD_TRACK_ID_MP3:
> +            par->codec_id              = AV_CODEC_ID_MP3;
> +            ffstream(st)->need_parsing = AVSTREAM_PARSE_FULL_RAW;
> +            break;
> +        case SCD_TRACK_ID_OGG:
> +        case SCD_TRACK_ID_MS_ADPCM:
> +        default:
> +            par->codec_id              = AV_CODEC_ID_NONE;
> +            avpriv_request_sample(s, "data type %u", track->data_type);
> +    }
> +
> +    return 0;
> +}
> +
> +static int scd_read_header(AVFormatContext *s)
> +{
> +    int64_t ret;
> +    SCDDemuxContext *ctx = s->priv_data;
> +    uint8_t buf[SCD_MIN_HEADER_SIZE];
> +
> +    if ((ret = avio_read(s->pb, buf, SCD_MIN_HEADER_SIZE)) < 0)
> +        return ret;
> +
> +    ctx->hdr.magic       = AV_RB64(buf +  0);
> +    ctx->hdr.version     = AV_RB32(buf +  8);
> +    ctx->hdr.unk1        = AV_RB16(buf + 12);
> +    ctx->hdr.header_size = AV_RB16(buf + 14);
> +    ctx->hdr.file_size   = AV_RB32(buf + 16);
> +
> +    if (ctx->hdr.magic != SCD_MAGIC)
> +        return AVERROR_INVALIDDATA;
> +
> +    if (ctx->hdr.version != 3) {
> +        avpriv_request_sample(s, "SCD version %u", ctx->hdr.version);
> +        return AVERROR_PATCHWELCOME;
> +    }
> +
> +    if (ctx->hdr.header_size < SCD_MIN_HEADER_SIZE)
> +        return AVERROR_INVALIDDATA;
> +
> +    if ((ret = avio_skip(s->pb, ctx->hdr.header_size - SCD_MIN_HEADER_SIZE)) < 0)
> +        return ret;
> +
> +    if ((ret = scd_read_offsets(s)) < 0)
> +        return ret;
> +
> +    ctx->tracks = av_calloc(ctx->hdr.table1.count, sizeof(SCDTrackHeader));
> +    if (ctx->tracks == NULL)
> +        return AVERROR(ENOMEM);
> +
> +    for (int i = 0; i < ctx->hdr.table1.count; i++) {
> +        if ((ret = scd_read_track(s, ctx->tracks + i, i)) < 0)
> +            return ret;
> +    }
> +
> +    if (ctx->hdr.table1.count == 0)
> +        return 0;
> +
> +    if ((ret = avio_seek(s->pb, ctx->tracks[0].absolute_offset, SEEK_SET)) < 0)
> +        return ret;
> +
> +    return 0;
> +}
> +
> +static int scd_read_packet(AVFormatContext *s, AVPacket *pkt)
> +{
> +    SCDDemuxContext   *ctx = s->priv_data;
> +    AVCodecParameters *par;
> +
> +    /* Streams aren't interleaved, round-robin them. */
> +    for (int i = 0; i < ctx->hdr.table1.count; i++) {
> +        int64_t ret;
> +        int size;
> +        SCDTrackHeader *trk;
> +
> +        ctx->current_track %= ctx->hdr.table1.count;
> +
> +        trk = ctx->tracks + ctx->current_track;
> +        par = s->streams[ctx->current_track]->codecpar;
> +
> +        if (trk->bytes_read >= trk->length)
> +            continue;
> +
> +        if ((ret = avio_seek(s->pb, trk->absolute_offset + trk->bytes_read, SEEK_SET)) < 0)
> +            return ret;
> +
> +        switch(trk->data_type) {
> +            case SCD_TRACK_ID_PCM:
> +                size = par->block_align;
> +                break;
> +            case SCD_TRACK_ID_MP3:
> +            default:
> +                size = FFMIN(trk->length - trk->bytes_read, 4096);
> +                break;
> +        }
> +
> +        ret = av_get_packet(s->pb, pkt, size);
> +        if (ret == AVERROR_EOF) {
> +            trk->length = trk->bytes_read;
> +            continue;
> +        } else if (ret < 0) {
> +            return ret;
> +        }
> +
> +        if (trk->data_type == SCD_TRACK_ID_PCM) {
> +            pkt->pts      = trk->bytes_read / (par->channels * sizeof(uint16_t));
> +            pkt->duration = size / (par->channels * sizeof(int16_t));
> +        }
> +
> +        trk->bytes_read   += ret;
> +        pkt->flags        &= ~AV_PKT_FLAG_CORRUPT;
> +        pkt->stream_index  = ctx->current_track;
> +
> +        ctx->current_track++;
> +        return 0;
> +    }
> +
> +    return AVERROR_EOF;
> +}
> +
> +static int scd_seek(AVFormatContext *s, int stream_index,
> +                    int64_t pts, int flags)
> +{
> +    SCDDemuxContext *ctx = s->priv_data;
> +    SCDTrackHeader  *trk = ctx->tracks + stream_index;
> +
> +    if (pts != 0)
> +        return AVERROR(EINVAL);
> +
> +    trk->bytes_read = 0;
> +    return 0;
> +
> +}
> +static int scd_read_close(AVFormatContext *s)
> +{
> +    SCDDemuxContext *ctx = s->priv_data;
> +
> +    av_freep(&ctx->hdr.table0.entries);
> +    av_freep(&ctx->hdr.table1.entries);
> +    av_freep(&ctx->hdr.table2.entries);
> +    av_freep(&ctx->tracks);
> +    return 0;
> +}
> +
> +const AVInputFormat ff_scd_demuxer = {
> +    .name           = "scd",
> +    .long_name      = NULL_IF_CONFIG_SMALL("Square Enix SCD"),
> +    .priv_data_size = sizeof(SCDDemuxContext),
> +    .flags_internal = FF_FMT_INIT_CLEANUP,
> +    .read_probe     = scd_probe,
> +    .read_header    = scd_read_header,
> +    .read_packet    = scd_read_packet,
> +    .read_seek      = scd_seek,
> +    .read_close     = scd_read_close,
> +};
> 


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