ffmpeg/libavcodec/smvjpegdec.c

188 lines
5.6 KiB
C

/*
* SMV JPEG decoder
* Copyright (c) 2013 Ash Hughes
*
* 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
* SMV JPEG decoder.
*/
// #define DEBUG
#include "avcodec.h"
#include "libavutil/opt.h"
#include "libavutil/imgutils.h"
#include "mjpegdec.h"
#include "internal.h"
typedef struct SMVJpegDecodeContext {
MJpegDecodeContext jpg;
AVFrame *picture[2]; /* pictures array */
AVCodecContext* avctx;
int frames_per_jpeg;
} SMVJpegDecodeContext;
static inline void smv_img_pnt_plane(uint8_t **dst, uint8_t *src,
int src_linesize, int height, int nlines)
{
if (!dst || !src)
return;
src += (nlines) * src_linesize * height;
*dst = src;
}
static inline void smv_img_pnt(uint8_t *dst_data[4], uint8_t *src_data[4],
const int src_linesizes[4],
enum PixelFormat pix_fmt, int width, int height,
int nlines)
{
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
int i, planes_nb = 0;
if (desc->flags & PIX_FMT_HWACCEL)
return;
for (i = 0; i < desc->nb_components; i++)
planes_nb = FFMAX(planes_nb, desc->comp[i].plane + 1);
for (i = 0; i < planes_nb; i++) {
int h = height;
if (i == 1 || i == 2) {
h = FF_CEIL_RSHIFT(height, desc->log2_chroma_h);
}
smv_img_pnt_plane(&dst_data[i], src_data[i],
src_linesizes[i], h, nlines);
}
}
static av_cold int smvjpeg_decode_init(AVCodecContext *avctx)
{
SMVJpegDecodeContext *s = avctx->priv_data;
AVCodec *codec;
AVDictionary *thread_opt = NULL;
int ret = 0;
s->frames_per_jpeg = 0;
s->picture[0] = av_frame_alloc();
if (!s->picture[0])
return AVERROR(ENOMEM);
s->picture[1] = av_frame_alloc();
if (!s->picture[1])
return AVERROR(ENOMEM);
s->jpg.picture_ptr = s->picture[0];
if (avctx->extradata_size >= 4)
s->frames_per_jpeg = AV_RL32(avctx->extradata);
if (s->frames_per_jpeg <= 0) {
av_log(avctx, AV_LOG_ERROR, "Invalid number of frames per jpeg.\n");
ret = -1;
}
avcodec_get_frame_defaults(s->picture[1]);
avctx->coded_frame = s->picture[1];
codec = avcodec_find_decoder(AV_CODEC_ID_MJPEG);
if (!codec) {
av_log(avctx, AV_LOG_ERROR, "MJPEG codec not found\n");
ret = -1;
}
s->avctx = avcodec_alloc_context3(codec);
av_dict_set(&thread_opt, "threads", "1", 0);
if (ff_codec_open2_recursive(s->avctx, codec, &thread_opt) < 0) {
av_log(avctx, AV_LOG_ERROR, "MJPEG codec failed to open\n");
ret = -1;
}
av_dict_free(&thread_opt);
return ret;
}
static int smvjpeg_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
AVPacket *avpkt)
{
SMVJpegDecodeContext *s = avctx->priv_data;
AVFrame* mjpeg_data = s->picture[0];
int i, cur_frame = 0, ret = 0;
cur_frame = avpkt->pts % s->frames_per_jpeg;
/* Are we at the start of a block? */
if (!cur_frame)
ret = avcodec_decode_video2(s->avctx, mjpeg_data, data_size, avpkt);
else /*use the last lot... */
*data_size = sizeof(AVPicture);
avctx->pix_fmt = s->avctx->pix_fmt;
/* We shouldn't get here if frames_per_jpeg <= 0 because this was rejected
in init */
avcodec_set_dimensions(avctx, mjpeg_data->width,
mjpeg_data->height / s->frames_per_jpeg);
s->picture[1]->extended_data = NULL;
s->picture[1]->width = avctx->width;
s->picture[1]->height = avctx->height;
s->picture[1]->format = avctx->pix_fmt;
/* ff_init_buffer_info(avctx, &s->picture[1]); */
smv_img_pnt(s->picture[1]->data, mjpeg_data->data, mjpeg_data->linesize,
avctx->pix_fmt, avctx->width, avctx->height, cur_frame);
for (i = 0; i < AV_NUM_DATA_POINTERS; i++)
s->picture[1]->linesize[i] = mjpeg_data->linesize[i];
ret = av_frame_ref(data, s->picture[1]);
return ret;
}
static av_cold int smvjpeg_decode_end(AVCodecContext *avctx)
{
SMVJpegDecodeContext *s = avctx->priv_data;
MJpegDecodeContext *jpg = &s->jpg;
jpg->picture_ptr = NULL;
av_frame_free(&s->picture[1]);
ff_codec_close_recursive(s->avctx);
av_freep(&s->avctx);
return 0;
}
static const AVClass smvjpegdec_class = {
.class_name = "SMVJPEG decoder",
.item_name = av_default_item_name,
.version = LIBAVUTIL_VERSION_INT,
};
AVCodec ff_smvjpeg_decoder = {
.name = "smvjpeg",
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_SMVJPEG,
.priv_data_size = sizeof(SMVJpegDecodeContext),
.init = smvjpeg_decode_init,
.close = smvjpeg_decode_end,
.decode = smvjpeg_decode_frame,
.max_lowres = 3,
.long_name = NULL_IF_CONFIG_SMALL("SMV JPEG"),
.priv_class = &smvjpegdec_class,
};