| /* |
| * 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, |
| }; |