FFmpeg/libavformat/mm.c
Andreas Rheinhardt c1e439d7e9 avformat: Forward errors where possible
It is not uncommon to find code where the caller thinks to know better
what the return value should be than the callee. E.g. something like
"if (av_new_packet(pkt, size) < 0) return AVERROR(ENOMEM);". This commit
changes several instances of this to instead forward the actual error.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2019-12-12 19:25:33 +01:00

199 lines
5.9 KiB
C

/*
* American Laser Games MM Format Demuxer
* Copyright (c) 2006 Peter Ross
*
* 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
* American Laser Games MM Format Demuxer
* by Peter Ross (pross@xvid.org)
*
* The MM format was used by IBM-PC ports of ALG's "arcade shooter" games,
* including Mad Dog McCree and Crime Patrol.
*
* Technical details here:
* http://wiki.multimedia.cx/index.php?title=American_Laser_Games_MM
*/
#include "libavutil/channel_layout.h"
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#include "internal.h"
#define MM_PREAMBLE_SIZE 6
#define MM_TYPE_HEADER 0x0
#define MM_TYPE_INTER 0x5
#define MM_TYPE_INTRA 0x8
#define MM_TYPE_INTRA_HH 0xc
#define MM_TYPE_INTER_HH 0xd
#define MM_TYPE_INTRA_HHV 0xe
#define MM_TYPE_INTER_HHV 0xf
#define MM_TYPE_AUDIO 0x15
#define MM_TYPE_PALETTE 0x31
#define MM_HEADER_LEN_V 0x16 /* video only */
#define MM_HEADER_LEN_AV 0x18 /* video + audio */
#define MM_PALETTE_COUNT 128
#define MM_PALETTE_SIZE (MM_PALETTE_COUNT*3)
typedef struct MmDemuxContext {
unsigned int audio_pts, video_pts;
} MmDemuxContext;
static int probe(const AVProbeData *p)
{
int len, type, fps, w, h;
if (p->buf_size < MM_HEADER_LEN_AV + MM_PREAMBLE_SIZE)
return 0;
/* the first chunk is always the header */
if (AV_RL16(&p->buf[0]) != MM_TYPE_HEADER)
return 0;
len = AV_RL32(&p->buf[2]);
if (len != MM_HEADER_LEN_V && len != MM_HEADER_LEN_AV)
return 0;
fps = AV_RL16(&p->buf[8]);
w = AV_RL16(&p->buf[12]);
h = AV_RL16(&p->buf[14]);
if (!fps || fps > 60 || !w || w > 2048 || !h || h > 2048)
return 0;
type = AV_RL16(&p->buf[len]);
if (!type || type > 0x31)
return 0;
/* only return half certainty since this check is a bit sketchy */
return AVPROBE_SCORE_EXTENSION;
}
static int read_header(AVFormatContext *s)
{
MmDemuxContext *mm = s->priv_data;
AVIOContext *pb = s->pb;
AVStream *st;
unsigned int type, length;
unsigned int frame_rate, width, height;
type = avio_rl16(pb);
length = avio_rl32(pb);
if (type != MM_TYPE_HEADER)
return AVERROR_INVALIDDATA;
/* read header */
avio_rl16(pb); /* total number of chunks */
frame_rate = avio_rl16(pb);
avio_rl16(pb); /* ibm-pc video bios mode */
width = avio_rl16(pb);
height = avio_rl16(pb);
avio_skip(pb, length - 10); /* unknown data */
/* video stream */
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->codec_id = AV_CODEC_ID_MMVIDEO;
st->codecpar->codec_tag = 0; /* no fourcc */
st->codecpar->width = width;
st->codecpar->height = height;
avpriv_set_pts_info(st, 64, 1, frame_rate);
/* audio stream */
if (length == MM_HEADER_LEN_AV) {
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_tag = 0; /* no fourcc */
st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
st->codecpar->channels = 1;
st->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
st->codecpar->sample_rate = 8000;
avpriv_set_pts_info(st, 64, 1, 8000); /* 8000 hz */
}
mm->audio_pts = 0;
mm->video_pts = 0;
return 0;
}
static int read_packet(AVFormatContext *s,
AVPacket *pkt)
{
MmDemuxContext *mm = s->priv_data;
AVIOContext *pb = s->pb;
unsigned char preamble[MM_PREAMBLE_SIZE];
unsigned int type, length;
int ret;
while(1) {
if (avio_read(pb, preamble, MM_PREAMBLE_SIZE) != MM_PREAMBLE_SIZE) {
return AVERROR(EIO);
}
type = AV_RL16(&preamble[0]);
length = AV_RL16(&preamble[2]);
switch(type) {
case MM_TYPE_PALETTE :
case MM_TYPE_INTER :
case MM_TYPE_INTRA :
case MM_TYPE_INTRA_HH :
case MM_TYPE_INTER_HH :
case MM_TYPE_INTRA_HHV :
case MM_TYPE_INTER_HHV :
/* output preamble + data */
if ((ret = av_new_packet(pkt, length + MM_PREAMBLE_SIZE)) < 0)
return ret;
memcpy(pkt->data, preamble, MM_PREAMBLE_SIZE);
if (avio_read(pb, pkt->data + MM_PREAMBLE_SIZE, length) != length)
return AVERROR(EIO);
pkt->size = length + MM_PREAMBLE_SIZE;
pkt->stream_index = 0;
pkt->pts = mm->video_pts;
if (type!=MM_TYPE_PALETTE)
mm->video_pts++;
return 0;
case MM_TYPE_AUDIO :
if ((ret = av_get_packet(s->pb, pkt, length)) < 0)
return ret;
pkt->stream_index = 1;
pkt->pts = mm->audio_pts++;
return 0;
default :
av_log(s, AV_LOG_INFO, "unknown chunk type 0x%x\n", type);
avio_skip(pb, length);
}
}
}
AVInputFormat ff_mm_demuxer = {
.name = "mm",
.long_name = NULL_IF_CONFIG_SMALL("American Laser Games MM"),
.priv_data_size = sizeof(MmDemuxContext),
.read_probe = probe,
.read_header = read_header,
.read_packet = read_packet,
};