[deb_ffmpeg.git] / ffmpeg / libavformat / 4xm.c

/*
 * 4X Technologies .4xm File Demuxer (no muxer)
 * Copyright (c) 2003  The FFmpeg Project
 *
 * 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
 * 4X Technologies file demuxer
 * by Mike Melanson (melanson@pcisys.net)
 * for more information on the .4xm file format, visit:
 *   http://www.pcisys.net/~melanson/codecs/
 */

#include "libavutil/intreadwrite.h"
#include "libavutil/intfloat.h"
#include "avformat.h"
#include "internal.h"

#define     RIFF_TAG MKTAG('R', 'I', 'F', 'F')
#define  FOURXMV_TAG MKTAG('4', 'X', 'M', 'V')
#define     LIST_TAG MKTAG('L', 'I', 'S', 'T')
#define     HEAD_TAG MKTAG('H', 'E', 'A', 'D')
#define     TRK__TAG MKTAG('T', 'R', 'K', '_')
#define     MOVI_TAG MKTAG('M', 'O', 'V', 'I')
#define     VTRK_TAG MKTAG('V', 'T', 'R', 'K')
#define     STRK_TAG MKTAG('S', 'T', 'R', 'K')
#define     std__TAG MKTAG('s', 't', 'd', '_')
#define     name_TAG MKTAG('n', 'a', 'm', 'e')
#define     vtrk_TAG MKTAG('v', 't', 'r', 'k')
#define     strk_TAG MKTAG('s', 't', 'r', 'k')
#define     ifrm_TAG MKTAG('i', 'f', 'r', 'm')
#define     pfrm_TAG MKTAG('p', 'f', 'r', 'm')
#define     cfrm_TAG MKTAG('c', 'f', 'r', 'm')
#define     ifr2_TAG MKTAG('i', 'f', 'r', '2')
#define     pfr2_TAG MKTAG('p', 'f', 'r', '2')
#define     cfr2_TAG MKTAG('c', 'f', 'r', '2')
#define     snd__TAG MKTAG('s', 'n', 'd', '_')

#define vtrk_SIZE 0x44
#define strk_SIZE 0x28

#define GET_LIST_HEADER() \
    fourcc_tag = avio_rl32(pb); \
    size       = avio_rl32(pb); \
    if (fourcc_tag != LIST_TAG) \
        return AVERROR_INVALIDDATA; \
    fourcc_tag = avio_rl32(pb);

typedef struct AudioTrack {
    int sample_rate;
    int bits;
    int channels;
    int stream_index;
    int adpcm;
    int64_t audio_pts;
} AudioTrack;

typedef struct FourxmDemuxContext {
    int video_stream_index;
    int track_count;
    AudioTrack *tracks;

    int64_t video_pts;
    float fps;
} FourxmDemuxContext;

static int fourxm_probe(AVProbeData *p)
{
    if ((AV_RL32(&p->buf[0]) != RIFF_TAG) ||
        (AV_RL32(&p->buf[8]) != FOURXMV_TAG))
        return 0;

    return AVPROBE_SCORE_MAX;
}

static int parse_vtrk(AVFormatContext *s,
                      FourxmDemuxContext *fourxm, uint8_t *buf, int size,
                      int left)
{
    AVStream *st;
    /* check that there is enough data */
    if (size != vtrk_SIZE || left < size + 8) {
        return AVERROR_INVALIDDATA;
    }

    /* allocate a new AVStream */
    st = avformat_new_stream(s, NULL);
    if (!st)
        return AVERROR(ENOMEM);

    avpriv_set_pts_info(st, 60, 1, fourxm->fps);

    fourxm->video_stream_index = st->index;

    st->codec->codec_type     = AVMEDIA_TYPE_VIDEO;
    st->codec->codec_id       = AV_CODEC_ID_4XM;

    st->codec->extradata      = av_mallocz(4 + FF_INPUT_BUFFER_PADDING_SIZE);
    if (!st->codec->extradata)
        return AVERROR(ENOMEM);
    st->codec->extradata_size = 4;
    AV_WL32(st->codec->extradata, AV_RL32(buf + 16));
    st->codec->width  = AV_RL32(buf + 36);
    st->codec->height = AV_RL32(buf + 40);

    return 0;
}


static int parse_strk(AVFormatContext *s,
                      FourxmDemuxContext *fourxm, uint8_t *buf, int size,
                      int left)
{
    AVStream *st;
    int track;
    /* check that there is enough data */
    if (size != strk_SIZE || left < size + 8)
        return AVERROR_INVALIDDATA;

    track = AV_RL32(buf + 8);
    if ((unsigned)track >= UINT_MAX / sizeof(AudioTrack) - 1) {
        av_log(s, AV_LOG_ERROR, "current_track too large\n");
        return AVERROR_INVALIDDATA;
    }

    if (track + 1 > fourxm->track_count) {
        if (av_reallocp_array(&fourxm->tracks, track + 1, sizeof(AudioTrack)))
            return AVERROR(ENOMEM);
        memset(&fourxm->tracks[fourxm->track_count], 0,
               sizeof(AudioTrack) * (track + 1 - fourxm->track_count));
        fourxm->track_count = track + 1;
    }
    fourxm->tracks[track].adpcm       = AV_RL32(buf + 12);
    fourxm->tracks[track].channels    = AV_RL32(buf + 36);
    fourxm->tracks[track].sample_rate = AV_RL32(buf + 40);
    fourxm->tracks[track].bits        = AV_RL32(buf + 44);
    fourxm->tracks[track].audio_pts   = 0;

    if (fourxm->tracks[track].channels    <= 0 ||
        fourxm->tracks[track].sample_rate <= 0 ||
        fourxm->tracks[track].bits        <= 0) {
        av_log(s, AV_LOG_ERROR, "audio header invalid\n");
        return AVERROR_INVALIDDATA;
    }
    if (!fourxm->tracks[track].adpcm && fourxm->tracks[track].bits<8) {
        av_log(s, AV_LOG_ERROR, "bits unspecified for non ADPCM\n");
        return AVERROR_INVALIDDATA;
    }

    /* allocate a new AVStream */
    st = avformat_new_stream(s, NULL);
    if (!st)
        return AVERROR(ENOMEM);

    st->id = track;
    avpriv_set_pts_info(st, 60, 1, fourxm->tracks[track].sample_rate);

    fourxm->tracks[track].stream_index = st->index;

    st->codec->codec_type            = AVMEDIA_TYPE_AUDIO;
    st->codec->codec_tag             = 0;
    st->codec->channels              = fourxm->tracks[track].channels;
    st->codec->sample_rate           = fourxm->tracks[track].sample_rate;
    st->codec->bits_per_coded_sample = fourxm->tracks[track].bits;
    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;

    if (fourxm->tracks[track].adpcm){
        st->codec->codec_id = AV_CODEC_ID_ADPCM_4XM;
    } else if (st->codec->bits_per_coded_sample == 8) {
        st->codec->codec_id = AV_CODEC_ID_PCM_U8;
    } else
        st->codec->codec_id = AV_CODEC_ID_PCM_S16LE;

    return 0;
}

static int fourxm_read_header(AVFormatContext *s)
{
    AVIOContext *pb = s->pb;
    unsigned int fourcc_tag;
    unsigned int size;
    int header_size;
    FourxmDemuxContext *fourxm = s->priv_data;
    unsigned char *header;
    int i, ret;

    fourxm->track_count = 0;
    fourxm->tracks      = NULL;
    fourxm->fps         = 1.0;

    /* skip the first 3 32-bit numbers */
    avio_skip(pb, 12);

    /* check for LIST-HEAD */
    GET_LIST_HEADER();
    header_size = size - 4;
    if (fourcc_tag != HEAD_TAG || header_size < 0)
        return AVERROR_INVALIDDATA;

    /* allocate space for the header and load the whole thing */
    header = av_malloc(header_size);
    if (!header)
        return AVERROR(ENOMEM);
    if (avio_read(pb, header, header_size) != header_size) {
        av_free(header);
        return AVERROR(EIO);
    }

    /* take the lazy approach and search for any and all vtrk and strk chunks */
    for (i = 0; i < header_size - 8; i++) {
        fourcc_tag = AV_RL32(&header[i]);
        size       = AV_RL32(&header[i + 4]);
        if (size > header_size - i - 8 && (fourcc_tag == vtrk_TAG || fourcc_tag == strk_TAG)) {
            av_log(s, AV_LOG_ERROR, "chunk larger than array %d>%d\n", size, header_size - i - 8);
            return AVERROR_INVALIDDATA;
        }

        if (fourcc_tag == std__TAG) {
            if (header_size - i < 16) {
                av_log(s, AV_LOG_ERROR, "std TAG truncated\n");
                ret = AVERROR_INVALIDDATA;
                goto fail;
            }
            fourxm->fps = av_int2float(AV_RL32(&header[i + 12]));
        } else if (fourcc_tag == vtrk_TAG) {
            if ((ret = parse_vtrk(s, fourxm, header + i, size,
                                  header_size - i)) < 0)
                goto fail;

            i += 8 + size;
        } else if (fourcc_tag == strk_TAG) {
            if ((ret = parse_strk(s, fourxm, header + i, size,
                                  header_size - i)) < 0)
                goto fail;

            i += 8 + size;
        }
    }

    /* skip over the LIST-MOVI chunk (which is where the stream should be */
    GET_LIST_HEADER();
    if (fourcc_tag != MOVI_TAG) {
        ret = AVERROR_INVALIDDATA;
        goto fail;
    }

    av_free(header);
    /* initialize context members */
    fourxm->video_pts = -1;  /* first frame will push to 0 */

    return 0;
fail:
    av_freep(&fourxm->tracks);
    av_free(header);
    return ret;
}

static int fourxm_read_packet(AVFormatContext *s,
                              AVPacket *pkt)
{
    FourxmDemuxContext *fourxm = s->priv_data;
    AVIOContext *pb            = s->pb;
    unsigned int fourcc_tag;
    unsigned int size;
    int ret = 0;
    unsigned int track_number;
    int packet_read = 0;
    unsigned char header[8];
    int audio_frame_count;

    while (!packet_read) {
        if ((ret = avio_read(s->pb, header, 8)) < 0)
            return ret;
        fourcc_tag = AV_RL32(&header[0]);
        size       = AV_RL32(&header[4]);
        if (avio_feof(pb))
            return AVERROR(EIO);
        switch (fourcc_tag) {
        case LIST_TAG:
            /* this is a good time to bump the video pts */
            fourxm->video_pts++;

            /* skip the LIST-* tag and move on to the next fourcc */
            avio_rl32(pb);
            break;

        case ifrm_TAG:
        case pfrm_TAG:
        case cfrm_TAG:
        case ifr2_TAG:
        case pfr2_TAG:
        case cfr2_TAG:
            /* allocate 8 more bytes than 'size' to account for fourcc
             * and size */
            if (size + 8 < size || av_new_packet(pkt, size + 8))
                return AVERROR(EIO);
            pkt->stream_index = fourxm->video_stream_index;
            pkt->pts          = fourxm->video_pts;
            pkt->pos          = avio_tell(s->pb);
            memcpy(pkt->data, header, 8);
            ret = avio_read(s->pb, &pkt->data[8], size);

            if (ret < 0) {
                av_free_packet(pkt);
            } else {
                packet_read = 1;
                av_shrink_packet(pkt, ret + 8);
            }
            break;

        case snd__TAG:
            track_number = avio_rl32(pb);
            avio_skip(pb, 4);
            size -= 8;

            if (track_number < fourxm->track_count &&
                fourxm->tracks[track_number].channels > 0) {
                ret = av_get_packet(s->pb, pkt, size);
                if (ret < 0)
                    return AVERROR(EIO);
                pkt->stream_index =
                    fourxm->tracks[track_number].stream_index;
                pkt->pts    = fourxm->tracks[track_number].audio_pts;
                packet_read = 1;

                /* pts accounting */
                audio_frame_count = size;
                if (fourxm->tracks[track_number].adpcm)
                    audio_frame_count -= 2 * (fourxm->tracks[track_number].channels);
                audio_frame_count /= fourxm->tracks[track_number].channels;
                if (fourxm->tracks[track_number].adpcm) {
                    audio_frame_count *= 2;
                } else
                    audio_frame_count /=
                        (fourxm->tracks[track_number].bits / 8);
                fourxm->tracks[track_number].audio_pts += audio_frame_count;
            } else {
                avio_skip(pb, size);
            }
            break;

        default:
            avio_skip(pb, size);
            break;
        }
    }
    return ret;
}

static int fourxm_read_close(AVFormatContext *s)
{
    FourxmDemuxContext *fourxm = s->priv_data;

    av_freep(&fourxm->tracks);

    return 0;
}

AVInputFormat ff_fourxm_demuxer = {
    .name           = "4xm",
    .long_name      = NULL_IF_CONFIG_SMALL("4X Technologies"),
    .priv_data_size = sizeof(FourxmDemuxContext),
    .read_probe     = fourxm_probe,
    .read_header    = fourxm_read_header,
    .read_packet    = fourxm_read_packet,
    .read_close     = fourxm_read_close,
};
Commit	Line	Data
2ba45a60 DM	1	/*
	2	* 4X Technologies .4xm File Demuxer (no muxer)
	3	* Copyright (c) 2003 The FFmpeg Project
	4	*
	5	* This file is part of FFmpeg.
	6	*
	7	* FFmpeg is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU Lesser General Public
	9	* License as published by the Free Software Foundation; either
	10	* version 2.1 of the License, or (at your option) any later version.
	11	*
	12	* FFmpeg is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	15	* Lesser General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU Lesser General Public
	18	* License along with FFmpeg; if not, write to the Free Software
	19	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	20	*/
	21
	22	/**
	23	* @file
	24	* 4X Technologies file demuxer
	25	* by Mike Melanson (melanson@pcisys.net)
	26	* for more information on the .4xm file format, visit:
	27	* http://www.pcisys.net/~melanson/codecs/
	28	*/
	29
	30	#include "libavutil/intreadwrite.h"
	31	#include "libavutil/intfloat.h"
	32	#include "avformat.h"
	33	#include "internal.h"
	34
	35	#define RIFF_TAG MKTAG('R', 'I', 'F', 'F')
	36	#define FOURXMV_TAG MKTAG('4', 'X', 'M', 'V')
	37	#define LIST_TAG MKTAG('L', 'I', 'S', 'T')
	38	#define HEAD_TAG MKTAG('H', 'E', 'A', 'D')
	39	#define TRK__TAG MKTAG('T', 'R', 'K', '_')
	40	#define MOVI_TAG MKTAG('M', 'O', 'V', 'I')
	41	#define VTRK_TAG MKTAG('V', 'T', 'R', 'K')
	42	#define STRK_TAG MKTAG('S', 'T', 'R', 'K')
	43	#define std__TAG MKTAG('s', 't', 'd', '_')
	44	#define name_TAG MKTAG('n', 'a', 'm', 'e')
	45	#define vtrk_TAG MKTAG('v', 't', 'r', 'k')
	46	#define strk_TAG MKTAG('s', 't', 'r', 'k')
	47	#define ifrm_TAG MKTAG('i', 'f', 'r', 'm')
	48	#define pfrm_TAG MKTAG('p', 'f', 'r', 'm')
	49	#define cfrm_TAG MKTAG('c', 'f', 'r', 'm')
	50	#define ifr2_TAG MKTAG('i', 'f', 'r', '2')
	51	#define pfr2_TAG MKTAG('p', 'f', 'r', '2')
	52	#define cfr2_TAG MKTAG('c', 'f', 'r', '2')
	53	#define snd__TAG MKTAG('s', 'n', 'd', '_')
	54
	55	#define vtrk_SIZE 0x44
	56	#define strk_SIZE 0x28
	57
	58	#define GET_LIST_HEADER() \
	59	fourcc_tag = avio_rl32(pb); \
	60	size = avio_rl32(pb); \
	61	if (fourcc_tag != LIST_TAG) \
	62	return AVERROR_INVALIDDATA; \
	63	fourcc_tag = avio_rl32(pb);
	64
65	typedef struct AudioTrack {
66	int sample_rate;
67	int bits;
68	int channels;
69	int stream_index;
70	int adpcm;
71	int64_t audio_pts;
72	} AudioTrack;
73
74	typedef struct FourxmDemuxContext {
75	int video_stream_index;
76	int track_count;
77	AudioTrack *tracks;
78
79	int64_t video_pts;
80	float fps;
81	} FourxmDemuxContext;
82
83	static int fourxm_probe(AVProbeData *p)
84	{
85	if ((AV_RL32(&p->buf[0]) != RIFF_TAG) \|\|
86	(AV_RL32(&p->buf[8]) != FOURXMV_TAG))
87	return 0;
88
89	return AVPROBE_SCORE_MAX;
90	}
91
92	static int parse_vtrk(AVFormatContext *s,
93	FourxmDemuxContext fourxm, uint8_t buf, int size,
94	int left)
95	{
96	AVStream *st;
97	/* check that there is enough data */
98	if (size != vtrk_SIZE \|\| left < size + 8) {
99	return AVERROR_INVALIDDATA;
100	}
101
102	/* allocate a new AVStream */
103	st = avformat_new_stream(s, NULL);
104	if (!st)
105	return AVERROR(ENOMEM);
106
107	avpriv_set_pts_info(st, 60, 1, fourxm->fps);
108
109	fourxm->video_stream_index = st->index;
110
111	st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
112	st->codec->codec_id = AV_CODEC_ID_4XM;
113
114	st->codec->extradata = av_mallocz(4 + FF_INPUT_BUFFER_PADDING_SIZE);
115	if (!st->codec->extradata)
116	return AVERROR(ENOMEM);
117	st->codec->extradata_size = 4;
118	AV_WL32(st->codec->extradata, AV_RL32(buf + 16));
119	st->codec->width = AV_RL32(buf + 36);
120	st->codec->height = AV_RL32(buf + 40);
121
122	return 0;
123	}
124
125
126	static int parse_strk(AVFormatContext *s,
127	FourxmDemuxContext fourxm, uint8_t buf, int size,
128	int left)
129	{
130	AVStream *st;
131	int track;
132	/* check that there is enough data */
133	if (size != strk_SIZE \|\| left < size + 8)
134	return AVERROR_INVALIDDATA;
135
136	track = AV_RL32(buf + 8);
137	if ((unsigned)track >= UINT_MAX / sizeof(AudioTrack) - 1) {
138	av_log(s, AV_LOG_ERROR, "current_track too large\n");
139	return AVERROR_INVALIDDATA;
140	}
141
142	if (track + 1 > fourxm->track_count) {
143	if (av_reallocp_array(&fourxm->tracks, track + 1, sizeof(AudioTrack)))
144	return AVERROR(ENOMEM);
145	memset(&fourxm->tracks[fourxm->track_count], 0,
146	sizeof(AudioTrack) * (track + 1 - fourxm->track_count));
147	fourxm->track_count = track + 1;
148	}
149	fourxm->tracks[track].adpcm = AV_RL32(buf + 12);
150	fourxm->tracks[track].channels = AV_RL32(buf + 36);
151	fourxm->tracks[track].sample_rate = AV_RL32(buf + 40);
152	fourxm->tracks[track].bits = AV_RL32(buf + 44);
153	fourxm->tracks[track].audio_pts = 0;
154
155	if (fourxm->tracks[track].channels <= 0 \|\|
156	fourxm->tracks[track].sample_rate <= 0 \|\|
157	fourxm->tracks[track].bits <= 0) {
158	av_log(s, AV_LOG_ERROR, "audio header invalid\n");
159	return AVERROR_INVALIDDATA;
160	}
161	if (!fourxm->tracks[track].adpcm && fourxm->tracks[track].bits<8) {
162	av_log(s, AV_LOG_ERROR, "bits unspecified for non ADPCM\n");
163	return AVERROR_INVALIDDATA;
164	}
165
166	/* allocate a new AVStream */
167	st = avformat_new_stream(s, NULL);
168	if (!st)
169	return AVERROR(ENOMEM);
170
171	st->id = track;
172	avpriv_set_pts_info(st, 60, 1, fourxm->tracks[track].sample_rate);
173
174	fourxm->tracks[track].stream_index = st->index;
175
176	st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
177	st->codec->codec_tag = 0;
178	st->codec->channels = fourxm->tracks[track].channels;
179	st->codec->sample_rate = fourxm->tracks[track].sample_rate;
180	st->codec->bits_per_coded_sample = fourxm->tracks[track].bits;
181	st->codec->bit_rate = st->codec->channels *
182	st->codec->sample_rate *
183	st->codec->bits_per_coded_sample;
184	st->codec->block_align = st->codec->channels *
185	st->codec->bits_per_coded_sample;
186
187	if (fourxm->tracks[track].adpcm){
188	st->codec->codec_id = AV_CODEC_ID_ADPCM_4XM;
189	} else if (st->codec->bits_per_coded_sample == 8) {
190	st->codec->codec_id = AV_CODEC_ID_PCM_U8;
191	} else
192	st->codec->codec_id = AV_CODEC_ID_PCM_S16LE;
193
194	return 0;
195	}
196
197	static int fourxm_read_header(AVFormatContext *s)
198	{
199	AVIOContext *pb = s->pb;
200	unsigned int fourcc_tag;
201	unsigned int size;
202	int header_size;
203	FourxmDemuxContext *fourxm = s->priv_data;
204	unsigned char *header;
205	int i, ret;
206
207	fourxm->track_count = 0;
208	fourxm->tracks = NULL;
209	fourxm->fps = 1.0;
210
211	/* skip the first 3 32-bit numbers */
212	avio_skip(pb, 12);
213
214	/* check for LIST-HEAD */
215	GET_LIST_HEADER();
216	header_size = size - 4;
217	if (fourcc_tag != HEAD_TAG \|\| header_size < 0)
218	return AVERROR_INVALIDDATA;
219
220	/* allocate space for the header and load the whole thing */
221	header = av_malloc(header_size);
222	if (!header)
223	return AVERROR(ENOMEM);
224	if (avio_read(pb, header, header_size) != header_size) {
225	av_free(header);
226	return AVERROR(EIO);
227	}
228
229	/* take the lazy approach and search for any and all vtrk and strk chunks */
230	for (i = 0; i < header_size - 8; i++) {
231	fourcc_tag = AV_RL32(&header[i]);
232	size = AV_RL32(&header[i + 4]);
233	if (size > header_size - i - 8 && (fourcc_tag == vtrk_TAG \|\| fourcc_tag == strk_TAG)) {
234	av_log(s, AV_LOG_ERROR, "chunk larger than array %d>%d\n", size, header_size - i - 8);
235	return AVERROR_INVALIDDATA;
236	}
237
238	if (fourcc_tag == std__TAG) {
239	if (header_size - i < 16) {
240	av_log(s, AV_LOG_ERROR, "std TAG truncated\n");
241	ret = AVERROR_INVALIDDATA;
242	goto fail;
243	}
244	fourxm->fps = av_int2float(AV_RL32(&header[i + 12]));
245	} else if (fourcc_tag == vtrk_TAG) {
246	if ((ret = parse_vtrk(s, fourxm, header + i, size,
247	header_size - i)) < 0)
248	goto fail;
249
250	i += 8 + size;
251	} else if (fourcc_tag == strk_TAG) {
252	if ((ret = parse_strk(s, fourxm, header + i, size,
253	header_size - i)) < 0)
254	goto fail;
255
256	i += 8 + size;
257	}
258	}
259
260	/* skip over the LIST-MOVI chunk (which is where the stream should be */
261	GET_LIST_HEADER();
262	if (fourcc_tag != MOVI_TAG) {
263	ret = AVERROR_INVALIDDATA;
264	goto fail;
265	}
266
267	av_free(header);
268	/* initialize context members */
269	fourxm->video_pts = -1; /* first frame will push to 0 */
270
271	return 0;
272	fail:
273	av_freep(&fourxm->tracks);
274	av_free(header);
275	return ret;
276	}
277
278	static int fourxm_read_packet(AVFormatContext *s,
279	AVPacket *pkt)
280	{
281	FourxmDemuxContext *fourxm = s->priv_data;
282	AVIOContext *pb = s->pb;
283	unsigned int fourcc_tag;
284	unsigned int size;
285	int ret = 0;
286	unsigned int track_number;
287	int packet_read = 0;
288	unsigned char header[8];
289	int audio_frame_count;
290
291	while (!packet_read) {
292	if ((ret = avio_read(s->pb, header, 8)) < 0)
293	return ret;
294	fourcc_tag = AV_RL32(&header[0]);
295	size = AV_RL32(&header[4]);
296	if (avio_feof(pb))
297	return AVERROR(EIO);
298	switch (fourcc_tag) {
299	case LIST_TAG:
300	/* this is a good time to bump the video pts */
301	fourxm->video_pts++;
302
303	/* skip the LIST-* tag and move on to the next fourcc */
304	avio_rl32(pb);
305	break;
306
307	case ifrm_TAG:
308	case pfrm_TAG:
309	case cfrm_TAG:
310	case ifr2_TAG:
311	case pfr2_TAG:
312	case cfr2_TAG:
313	/* allocate 8 more bytes than 'size' to account for fourcc
314	* and size */
315	if (size + 8 < size \|\| av_new_packet(pkt, size + 8))
316	return AVERROR(EIO);
317	pkt->stream_index = fourxm->video_stream_index;
318	pkt->pts = fourxm->video_pts;
319	pkt->pos = avio_tell(s->pb);
320	memcpy(pkt->data, header, 8);
321	ret = avio_read(s->pb, &pkt->data[8], size);
322
323	if (ret < 0) {
324	av_free_packet(pkt);
325	} else {
326	packet_read = 1;
327	av_shrink_packet(pkt, ret + 8);
328	}
329	break;
330
331	case snd__TAG:
332	track_number = avio_rl32(pb);
333	avio_skip(pb, 4);
334	size -= 8;
335
336	if (track_number < fourxm->track_count &&
337	fourxm->tracks[track_number].channels > 0) {
338	ret = av_get_packet(s->pb, pkt, size);
339	if (ret < 0)
340	return AVERROR(EIO);
341	pkt->stream_index =
342	fourxm->tracks[track_number].stream_index;
343	pkt->pts = fourxm->tracks[track_number].audio_pts;
344	packet_read = 1;
345
346	/* pts accounting */
347	audio_frame_count = size;
348	if (fourxm->tracks[track_number].adpcm)
349	audio_frame_count -= 2 * (fourxm->tracks[track_number].channels);
350	audio_frame_count /= fourxm->tracks[track_number].channels;
351	if (fourxm->tracks[track_number].adpcm) {
352	audio_frame_count *= 2;
353	} else
354	audio_frame_count /=
355	(fourxm->tracks[track_number].bits / 8);
356	fourxm->tracks[track_number].audio_pts += audio_frame_count;
357	} else {
358	avio_skip(pb, size);
359	}
360	break;
361
362	default:
363	avio_skip(pb, size);
364	break;
365	}
366	}
367	return ret;
368	}
369
370	static int fourxm_read_close(AVFormatContext *s)
371	{
372	FourxmDemuxContext *fourxm = s->priv_data;
373
374	av_freep(&fourxm->tracks);
375
376	return 0;
377	}
378
379	AVInputFormat ff_fourxm_demuxer = {
380	.name = "4xm",
381	.long_name = NULL_IF_CONFIG_SMALL("4X Technologies"),
382	.priv_data_size = sizeof(FourxmDemuxContext),
383	.read_probe = fourxm_probe,
384	.read_header = fourxm_read_header,
385	.read_packet = fourxm_read_packet,
386	.read_close = fourxm_read_close,
387	};