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/*
* Media 100 to MJPEGB bitstream filter
* Copyright (c) 2023 Paul B Mahol
*
* 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
* Media 100 to MJPEGB bitstream filter.
*/
#include "libavutil/intreadwrite.h"
#include "bsf.h"
#include "bsf_internal.h"
#include "bytestream.h"
static av_cold int init(AVBSFContext *ctx)
{
ctx->par_out->codec_id = AV_CODEC_ID_MJPEGB;
return 0;
}
static int filter(AVBSFContext *ctx, AVPacket *out)
{
unsigned second_field_offset = 0;
unsigned next_field = 0;
unsigned dht_offset[2];
unsigned dqt_offset[2];
unsigned sod_offset[2];
unsigned sof_offset[2];
unsigned sos_offset[2];
unsigned field = 0;
GetByteContext gb;
PutByteContext pb;
AVPacket *in;
int ret;
ret = ff_bsf_get_packet(ctx, &in);
if (ret < 0)
return ret;
ret = av_new_packet(out, in->size + 1024);
if (ret < 0)
goto fail;
bytestream2_init(&gb, in->data, in->size);
bytestream2_init_writer(&pb, out->data, out->size);
second_field:
bytestream2_put_be32(&pb, 0);
bytestream2_put_be32(&pb, AV_RB32("mjpg"));
bytestream2_put_be32(&pb, 0);
bytestream2_put_be32(&pb, 0);
for (int i = 0; i < 6; i++)
bytestream2_put_be32(&pb, 0);
sof_offset[field] = bytestream2_tell_p(&pb);
bytestream2_put_be16(&pb, 17);
bytestream2_put_byte(&pb, 8);
bytestream2_put_be16(&pb, ctx->par_in->height / 2);
bytestream2_put_be16(&pb, ctx->par_in->width);
bytestream2_put_byte(&pb, 3);
bytestream2_put_byte(&pb, 1);
bytestream2_put_byte(&pb, 0x21);
bytestream2_put_byte(&pb, 0);
bytestream2_put_byte(&pb, 2);
bytestream2_put_byte(&pb, 0x11);
bytestream2_put_byte(&pb, 1);
bytestream2_put_byte(&pb, 3);
bytestream2_put_byte(&pb, 0x11);
bytestream2_put_byte(&pb, 1);
sos_offset[field] = bytestream2_tell_p(&pb);
bytestream2_put_be16(&pb, 12);
bytestream2_put_byte(&pb, 3);
bytestream2_put_byte(&pb, 1);
bytestream2_put_byte(&pb, 0);
bytestream2_put_byte(&pb, 2);
bytestream2_put_byte(&pb, 0x11);
bytestream2_put_byte(&pb, 3);
bytestream2_put_byte(&pb, 0x11);
bytestream2_put_byte(&pb, 0);
bytestream2_put_byte(&pb, 0);
bytestream2_put_byte(&pb, 0);
dqt_offset[field] = bytestream2_tell_p(&pb);
bytestream2_put_be16(&pb, 132);
bytestream2_put_byte(&pb, 0);
bytestream2_skip(&gb, 4);
for (int i = 0; i < 64; i++)
bytestream2_put_byte(&pb, bytestream2_get_be32(&gb));
bytestream2_put_byte(&pb, 1);
for (int i = 0; i < 64; i++)
bytestream2_put_byte(&pb, bytestream2_get_be32(&gb));
dht_offset[field] = 0;
sod_offset[field] = bytestream2_tell_p(&pb);
for (int i = bytestream2_tell(&gb) + 8; next_field == 0 && i < in->size - 4; i++) {
if (AV_RB32(in->data + i) == 0x00000001) {
next_field = i;
break;
}
}
bytestream2_skip(&gb, 8);
bytestream2_copy_buffer(&pb, &gb, next_field - bytestream2_tell(&gb));
bytestream2_put_be64(&pb, 0);
if (field == 0) {
field = 1;
second_field_offset = bytestream2_tell_p(&pb);
next_field = in->size;
goto second_field;
}
AV_WB32(out->data + 8, second_field_offset);
AV_WB32(out->data + 12, second_field_offset);
AV_WB32(out->data + 16, second_field_offset);
AV_WB32(out->data + 20, dqt_offset[0]);
AV_WB32(out->data + 24, dht_offset[0]);
AV_WB32(out->data + 28, sof_offset[0]);
AV_WB32(out->data + 32, sos_offset[0]);
AV_WB32(out->data + 36, sod_offset[0]);
AV_WB32(out->data + second_field_offset + 8, bytestream2_tell_p(&pb) - second_field_offset);
AV_WB32(out->data + second_field_offset + 12, bytestream2_tell_p(&pb) - second_field_offset);
AV_WB32(out->data + second_field_offset + 16, 0);
AV_WB32(out->data + second_field_offset + 20, dqt_offset[1] - second_field_offset);
AV_WB32(out->data + second_field_offset + 24, dht_offset[1]);
AV_WB32(out->data + second_field_offset + 28, sof_offset[1] - second_field_offset);
AV_WB32(out->data + second_field_offset + 32, sos_offset[1] - second_field_offset);
AV_WB32(out->data + second_field_offset + 36, sod_offset[1] - second_field_offset);
out->size = bytestream2_tell_p(&pb);
ret = av_packet_copy_props(out, in);
if (ret < 0)
goto fail;
fail:
if (ret < 0)
av_packet_unref(out);
av_packet_free(&in);
return ret;
}
const FFBitStreamFilter ff_media100_to_mjpegb_bsf = {
.p.name = "media100_to_mjpegb",
.p.codec_ids = (const enum AVCodecID []){ AV_CODEC_ID_MEDIA100, AV_CODEC_ID_NONE },
.init = init,
.filter = filter,
};
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