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FFmpeg/libavformat/iff.c
Stefano Sabatini e280a4da2a iff/8svx: redesign 8SVX demuxing and decoding for handling stereo samples correctly 
Make the iff demuxer send the whole audio chunk to the decoder as a
single packet, move stereo interleaving from the iff demuxer to the
decoder, and introduce an 8svx_raw decoder which performs
stereo interleaving.

This is required for handling stereo data correctly, indeed samples
are stored like:
LLLLLL....RRRRRR

that is all left samples are at the beginning of the chunk, all right
samples at the end, so it is necessary to store and process the whole
buffer in order to decode each frame. Thus the decoder needs all the
audio chunk before it can return interleaved data.

Fix decoding of files 8svx_exp.iff and 8svx_fib.iff, fix trac issue #169.
2011-05-17 00:58:33 +02:00

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/*
* IFF (.iff) file demuxer
* Copyright (c) 2008 Jaikrishnan Menon <realityman@gmx.net>
* Copyright (c) 2010 Peter Ross <pross@xvid.org>
* Copyright (c) 2010 Sebastian Vater <cdgs.basty@googlemail.com>
*
* 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
* IFF file demuxer
* by Jaikrishnan Menon
* for more information on the .iff file format, visit:
* http://wiki.multimedia.cx/index.php?title=IFF
*/
#include "libavcodec/bytestream.h"
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#define ID_8SVX MKTAG('8','S','V','X')
#define ID_VHDR MKTAG('V','H','D','R')
#define ID_ATAK MKTAG('A','T','A','K')
#define ID_RLSE MKTAG('R','L','S','E')
#define ID_CHAN MKTAG('C','H','A','N')
#define ID_PBM MKTAG('P','B','M',' ')
#define ID_ILBM MKTAG('I','L','B','M')
#define ID_BMHD MKTAG('B','M','H','D')
#define ID_CAMG MKTAG('C','A','M','G')
#define ID_CMAP MKTAG('C','M','A','P')
#define ID_FORM MKTAG('F','O','R','M')
#define ID_ANNO MKTAG('A','N','N','O')
#define ID_AUTH MKTAG('A','U','T','H')
#define ID_CHRS MKTAG('C','H','R','S')
#define ID_COPYRIGHT MKTAG('(','c',')',' ')
#define ID_CSET MKTAG('C','S','E','T')
#define ID_FVER MKTAG('F','V','E','R')
#define ID_NAME MKTAG('N','A','M','E')
#define ID_TEXT MKTAG('T','E','X','T')
#define ID_BODY MKTAG('B','O','D','Y')
#define ID_ANNO MKTAG('A','N','N','O')
#define LEFT 2
#define RIGHT 4
#define STEREO 6
/**
* This number of bytes if added at the beginning of each AVPacket
* which contain additional information about video properties
* which has to be shared between demuxer and decoder.
* This number may change between frames, e.g. the demuxer might
* set it to smallest possible size of 2 to indicate that there's
* no extradata changing in this frame.
*/
#define IFF_EXTRA_VIDEO_SIZE 9
typedef enum {
COMP_NONE,
COMP_FIB,
COMP_EXP
} svx8_compression_type;
typedef enum {
BITMAP_RAW,
BITMAP_BYTERUN1
} bitmap_compression_type;
typedef struct {
uint64_t body_pos;
uint32_t body_size;
uint32_t sent_bytes;
uint32_t audio_frame_count;
svx8_compression_type svx8_compression;
bitmap_compression_type bitmap_compression; ///< delta compression method used
unsigned bpp; ///< bits per plane to decode (differs from bits_per_coded_sample if HAM)
unsigned ham; ///< 0 if non-HAM or number of hold bits (6 for bpp > 6, 4 otherwise)
unsigned flags; ///< 1 for EHB, 0 is no extra half darkening
unsigned transparency; ///< transparency color index in palette
unsigned masking; ///< masking method used
} IffDemuxContext;
/* Metadata string read */
static int get_metadata(AVFormatContext *s,
const char *const tag,
const unsigned data_size)
{
uint8_t *buf = ((data_size + 1) == 0) ? NULL : av_malloc(data_size + 1);
if (!buf)
return AVERROR(ENOMEM);
if (avio_read(s->pb, buf, data_size) < 0) {
av_free(buf);
return AVERROR(EIO);
}
buf[data_size] = 0;
av_metadata_set2(&s->metadata, tag, buf, AV_METADATA_DONT_STRDUP_VAL);
return 0;
}
static int iff_probe(AVProbeData *p)
{
const uint8_t *d = p->buf;
if ( AV_RL32(d) == ID_FORM &&
(AV_RL32(d+8) == ID_8SVX || AV_RL32(d+8) == ID_PBM || AV_RL32(d+8) == ID_ILBM) )
return AVPROBE_SCORE_MAX;
return 0;
}
static int iff_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
IffDemuxContext *iff = s->priv_data;
AVIOContext *pb = s->pb;
AVStream *st;
uint8_t *buf;
uint32_t chunk_id, data_size;
uint32_t screenmode = 0;
unsigned transparency = 0;
unsigned masking = 0; // no mask
st = av_new_stream(s, 0);
if (!st)
return AVERROR(ENOMEM);
st->codec->channels = 1;
avio_skip(pb, 8);
// codec_tag used by ByteRun1 decoder to distinguish progressive (PBM) and interlaced (ILBM) content
st->codec->codec_tag = avio_rl32(pb);
while(!url_feof(pb)) {
uint64_t orig_pos;
int res;
const char *metadata_tag = NULL;
chunk_id = avio_rl32(pb);
data_size = avio_rb32(pb);
orig_pos = avio_tell(pb);
switch(chunk_id) {
case ID_VHDR:
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
if (data_size < 14)
return AVERROR_INVALIDDATA;
avio_skip(pb, 12);
st->codec->sample_rate = avio_rb16(pb);
if (data_size >= 16) {
avio_skip(pb, 1);
iff->svx8_compression = avio_r8(pb);
}
break;
case ID_BODY:
iff->body_pos = avio_tell(pb);
iff->body_size = data_size;
break;
case ID_CHAN:
if (data_size < 4)
return AVERROR_INVALIDDATA;
st->codec->channels = (avio_rb32(pb) < 6) ? 1 : 2;
break;
case ID_CAMG:
if (data_size < 4)
return AVERROR_INVALIDDATA;
screenmode = avio_rb32(pb);
break;
case ID_CMAP:
st->codec->extradata_size = data_size + IFF_EXTRA_VIDEO_SIZE;
st->codec->extradata = av_malloc(data_size + IFF_EXTRA_VIDEO_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
if (!st->codec->extradata)
return AVERROR(ENOMEM);
if (avio_read(pb, st->codec->extradata + IFF_EXTRA_VIDEO_SIZE, data_size) < 0)
return AVERROR(EIO);
break;
case ID_BMHD:
iff->bitmap_compression = -1;
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
if (data_size <= 8)
return AVERROR_INVALIDDATA;
st->codec->width = avio_rb16(pb);
st->codec->height = avio_rb16(pb);
avio_skip(pb, 4); // x, y offset
st->codec->bits_per_coded_sample = avio_r8(pb);
if (data_size >= 10)
masking = avio_r8(pb);
if (data_size >= 11)
iff->bitmap_compression = avio_r8(pb);
if (data_size >= 14) {
avio_skip(pb, 1); // padding
transparency = avio_rb16(pb);
}
if (data_size >= 16) {
st->sample_aspect_ratio.num = avio_r8(pb);
st->sample_aspect_ratio.den = avio_r8(pb);
}
break;
case ID_ANNO:
case ID_TEXT: metadata_tag = "comment"; break;
case ID_AUTH: metadata_tag = "artist"; break;
case ID_COPYRIGHT: metadata_tag = "copyright"; break;
case ID_NAME: metadata_tag = "title"; break;
}
if (metadata_tag) {
if ((res = get_metadata(s, metadata_tag, data_size)) < 0) {
av_log(s, AV_LOG_ERROR, "cannot allocate metadata tag %s!", metadata_tag);
return res;
}
}
avio_skip(pb, data_size - (avio_tell(pb) - orig_pos) + (data_size & 1));
}
avio_seek(pb, iff->body_pos, SEEK_SET);
switch(st->codec->codec_type) {
case AVMEDIA_TYPE_AUDIO:
av_set_pts_info(st, 32, 1, st->codec->sample_rate);
switch (iff->svx8_compression) {
case COMP_NONE:
st->codec->codec_id = CODEC_ID_8SVX_RAW;
break;
case COMP_FIB:
st->codec->codec_id = CODEC_ID_8SVX_FIB;
break;
case COMP_EXP:
st->codec->codec_id = CODEC_ID_8SVX_EXP;
break;
default:
av_log(s, AV_LOG_ERROR,
"Unknown SVX8 compression method '%d'\n", iff->svx8_compression);
return -1;
}
st->codec->bits_per_coded_sample = iff->svx8_compression == COMP_NONE ? 8 : 4;
st->codec->bit_rate = st->codec->channels * st->codec->sample_rate * st->codec->bits_per_coded_sample;
st->codec->block_align = st->codec->channels * st->codec->bits_per_coded_sample;
break;
case AVMEDIA_TYPE_VIDEO:
iff->bpp = st->codec->bits_per_coded_sample;
if ((screenmode & 0x800 /* Hold And Modify */) && iff->bpp <= 8) {
iff->ham = iff->bpp > 6 ? 6 : 4;
st->codec->bits_per_coded_sample = 24;
}
iff->flags = (screenmode & 0x80 /* Extra HalfBrite */) && iff->bpp <= 8;
iff->masking = masking;
iff->transparency = transparency;
if (!st->codec->extradata) {
st->codec->extradata_size = IFF_EXTRA_VIDEO_SIZE;
st->codec->extradata = av_malloc(IFF_EXTRA_VIDEO_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
if (!st->codec->extradata)
return AVERROR(ENOMEM);
}
buf = st->codec->extradata;
bytestream_put_be16(&buf, IFF_EXTRA_VIDEO_SIZE);
bytestream_put_byte(&buf, iff->bitmap_compression);
bytestream_put_byte(&buf, iff->bpp);
bytestream_put_byte(&buf, iff->ham);
bytestream_put_byte(&buf, iff->flags);
bytestream_put_be16(&buf, iff->transparency);
bytestream_put_byte(&buf, iff->masking);
switch (iff->bitmap_compression) {
case BITMAP_RAW:
st->codec->codec_id = CODEC_ID_IFF_ILBM;
break;
case BITMAP_BYTERUN1:
st->codec->codec_id = CODEC_ID_IFF_BYTERUN1;
break;
default:
av_log(s, AV_LOG_ERROR,
"Unknown bitmap compression method '%d'\n", iff->bitmap_compression);
return AVERROR_INVALIDDATA;
}
break;
default:
return -1;
}
return 0;
}
static int iff_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
IffDemuxContext *iff = s->priv_data;
AVIOContext *pb = s->pb;
AVStream *st = s->streams[0];
int ret;
if(iff->sent_bytes >= iff->body_size)
return AVERROR(EIO);
if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
ret = av_get_packet(pb, pkt, iff->body_size);
} else if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
uint8_t *buf;
if (av_new_packet(pkt, iff->body_size + 2) < 0) {
return AVERROR(ENOMEM);
}
buf = pkt->data;
bytestream_put_be16(&buf, 2);
ret = avio_read(pb, buf, iff->body_size);
}
if(iff->sent_bytes == 0)
pkt->flags |= AV_PKT_FLAG_KEY;
iff->sent_bytes = iff->body_size;
pkt->stream_index = 0;
return ret;
}
AVInputFormat ff_iff_demuxer = {
"IFF",
NULL_IF_CONFIG_SMALL("IFF format"),
sizeof(IffDemuxContext),
iff_probe,
iff_read_header,
iff_read_packet,
};
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