yading@10: /*
yading@10:  * MJPEG/AVI1 to JPEG/JFIF bitstream format filter
yading@10:  * Copyright (c) 2010 Adrian Daerr and Nicolas George
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /*
yading@10:  * Adapted from mjpeg2jpeg.c, with original copyright:
yading@10:  * Paris 2010 Adrian Daerr, public domain
yading@10:  */
yading@10: 
yading@10: #include <string.h>
yading@10: #include "avcodec.h"
yading@10: #include "mjpeg.h"
yading@10: 
yading@10: static const uint8_t jpeg_header[] = {
yading@10:     0xff, 0xd8,                     // SOI
yading@10:     0xff, 0xe0,                     // APP0
yading@10:     0x00, 0x10,                     // APP0 header size (including
yading@10:                                     // this field, but excluding preceding)
yading@10:     0x4a, 0x46, 0x49, 0x46, 0x00,   // ID string 'JFIF\0'
yading@10:     0x01, 0x01,                     // version
yading@10:     0x00,                           // bits per type
yading@10:     0x00, 0x00,                     // X density
yading@10:     0x00, 0x00,                     // Y density
yading@10:     0x00,                           // X thumbnail size
yading@10:     0x00,                           // Y thumbnail size
yading@10: };
yading@10: 
yading@10: static const int dht_segment_size = 420;
yading@10: static const uint8_t dht_segment_head[] = { 0xFF, 0xC4, 0x01, 0xA2, 0x00 };
yading@10: static const uint8_t dht_segment_frag[] = {
yading@10:     0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
yading@10:     0x0a, 0x0b, 0x01, 0x00, 0x03, 0x01, 0x01, 0x01, 0x01, 0x01,
yading@10:     0x01, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
yading@10: };
yading@10: 
yading@10: static uint8_t *append(uint8_t *buf, const uint8_t *src, int size)
yading@10: {
yading@10:     memcpy(buf, src, size);
yading@10:     return buf + size;
yading@10: }
yading@10: 
yading@10: static uint8_t *append_dht_segment(uint8_t *buf)
yading@10: {
yading@10:     buf = append(buf, dht_segment_head, sizeof(dht_segment_head));
yading@10:     buf = append(buf, avpriv_mjpeg_bits_dc_luminance + 1, 16);
yading@10:     buf = append(buf, dht_segment_frag, sizeof(dht_segment_frag));
yading@10:     buf = append(buf, avpriv_mjpeg_val_dc, 12);
yading@10:     *(buf++) = 0x10;
yading@10:     buf = append(buf, avpriv_mjpeg_bits_ac_luminance + 1, 16);
yading@10:     buf = append(buf, avpriv_mjpeg_val_ac_luminance, 162);
yading@10:     *(buf++) = 0x11;
yading@10:     buf = append(buf, avpriv_mjpeg_bits_ac_chrominance + 1, 16);
yading@10:     buf = append(buf, avpriv_mjpeg_val_ac_chrominance, 162);
yading@10:     return buf;
yading@10: }
yading@10: 
yading@10: static int mjpeg2jpeg_filter(AVBitStreamFilterContext *bsfc,
yading@10:                              AVCodecContext *avctx, const char *args,
yading@10:                              uint8_t **poutbuf, int *poutbuf_size,
yading@10:                              const uint8_t *buf, int buf_size,
yading@10:                              int keyframe)
yading@10: {
yading@10:     int input_skip, output_size;
yading@10:     uint8_t *output, *out;
yading@10: 
yading@10:     if (buf_size < 12) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "input is truncated\n");
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10:     if (memcmp("AVI1", buf + 6, 4)) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "input is not MJPEG/AVI1\n");
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10:     input_skip = (buf[4] << 8) + buf[5] + 4;
yading@10:     if (buf_size < input_skip) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "input is truncated\n");
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10:     output_size = buf_size - input_skip +
yading@10:                   sizeof(jpeg_header) + dht_segment_size;
yading@10:     output = out = av_malloc(output_size);
yading@10:     if (!output)
yading@10:         return AVERROR(ENOMEM);
yading@10:     out = append(out, jpeg_header, sizeof(jpeg_header));
yading@10:     out = append_dht_segment(out);
yading@10:     out = append(out, buf + input_skip, buf_size - input_skip);
yading@10:     *poutbuf = output;
yading@10:     *poutbuf_size = output_size;
yading@10:     return 1;
yading@10: }
yading@10: 
yading@10: AVBitStreamFilter ff_mjpeg2jpeg_bsf = {
yading@10:     .name           = "mjpeg2jpeg",
yading@10:     .filter         = mjpeg2jpeg_filter,
yading@10: };