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ffmpeg/libav/asf.c

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/*
* ASF compatible encoder and decoder.
* Copyright (c) 2000, 2001 Gerard Lantau.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "avformat.h"
#include "avi.h"
#define PACKET_SIZE 3200
#define PACKET_HEADER_SIZE 12
#define FRAME_HEADER_SIZE 17
typedef struct {
int num;
int seq;
/* use for reading */
AVPacket pkt;
int frag_offset;
} ASFStream;
typedef struct {
int seqno;
int packet_size;
ASFStream streams[2];
/* non streamed additonnal info */
int data_offset;
INT64 nb_packets;
INT64 duration; /* in 100ns units */
/* packet filling */
int packet_size_left;
int packet_timestamp_start;
int packet_timestamp_end;
int packet_nb_frames;
UINT8 packet_buf[PACKET_SIZE];
ByteIOContext pb;
/* only for reading */
int packet_padsize;
} ASFContext;
typedef struct {
UINT32 v1;
UINT16 v2;
UINT16 v3;
UINT8 v4[8];
} GUID;
static const GUID asf_header = {
0x75B22630, 0x668E, 0x11CF, { 0xA6, 0xD9, 0x00, 0xAA, 0x00, 0x62, 0xCE, 0x6C },
};
static const GUID file_header = {
0x8CABDCA1, 0xA947, 0x11CF, { 0x8E, 0xE4, 0x00, 0xC0, 0x0C, 0x20, 0x53, 0x65 },
};
static const GUID stream_header = {
0xB7DC0791, 0xA9B7, 0x11CF, { 0x8E, 0xE6, 0x00, 0xC0, 0x0C, 0x20, 0x53, 0x65 },
};
static const GUID audio_stream = {
0xF8699E40, 0x5B4D, 0x11CF, { 0xA8, 0xFD, 0x00, 0x80, 0x5F, 0x5C, 0x44, 0x2B },
};
static const GUID audio_conceal_none = {
0x49f1a440, 0x4ece, 0x11d0, { 0xa3, 0xac, 0x00, 0xa0, 0xc9, 0x03, 0x48, 0xf6 },
};
static const GUID video_stream = {
0xBC19EFC0, 0x5B4D, 0x11CF, { 0xA8, 0xFD, 0x00, 0x80, 0x5F, 0x5C, 0x44, 0x2B },
};
static const GUID video_conceal_none = {
0x20FB5700, 0x5B55, 0x11CF, { 0xA8, 0xFD, 0x00, 0x80, 0x5F, 0x5C, 0x44, 0x2B },
};
static const GUID comment_header = {
0x75b22633, 0x668e, 0x11cf, { 0xa6, 0xd9, 0x00, 0xaa, 0x00, 0x62, 0xce, 0x6c },
};
static const GUID codec_comment_header = {
0x86D15240, 0x311D, 0x11D0, { 0xA3, 0xA4, 0x00, 0xA0, 0xC9, 0x03, 0x48, 0xF6 },
};
static const GUID codec_comment1_header = {
0x86d15241, 0x311d, 0x11d0, { 0xa3, 0xa4, 0x00, 0xa0, 0xc9, 0x03, 0x48, 0xf6 },
};
static const GUID data_header = {
0x75b22636, 0x668e, 0x11cf, { 0xa6, 0xd9, 0x00, 0xaa, 0x00, 0x62, 0xce, 0x6c },
};
static const GUID index_guid = {
0x33000890, 0xe5b1, 0x11cf, { 0x89, 0xf4, 0x00, 0xa0, 0xc9, 0x03, 0x49, 0xcb },
};
static const GUID head1_guid = {
0x5fbf03b5, 0xa92e, 0x11cf, { 0x8e, 0xe3, 0x00, 0xc0, 0x0c, 0x20, 0x53, 0x65 },
};
static const GUID head2_guid = {
0xabd3d211, 0xa9ba, 0x11cf, { 0x8e, 0xe6, 0x00, 0xc0, 0x0c, 0x20, 0x53, 0x65 },
};
/* I am not a number !!! This GUID is the one found on the PC used to
generate the stream */
static const GUID my_guid = {
0, 0, 0, { 0, 0, 0, 0, 0, 0, 0, 0 },
};
static void put_guid(ByteIOContext *s, const GUID *g)
{
int i;
put_le32(s, g->v1);
put_le16(s, g->v2);
put_le16(s, g->v3);
for(i=0;i<8;i++)
put_byte(s, g->v4[i]);
}
static void put_str16(ByteIOContext *s, const char *tag)
{
int c;
put_le16(s,strlen(tag) + 1);
for(;;) {
c = (UINT8)*tag++;
put_le16(s, c);
if (c == '\0')
break;
}
}
static void put_str16_nolen(ByteIOContext *s, const char *tag)
{
int c;
for(;;) {
c = (UINT8)*tag++;
put_le16(s, c);
if (c == '\0')
break;
}
}
static INT64 put_header(ByteIOContext *pb, const GUID *g)
{
INT64 pos;
pos = url_ftell(pb);
put_guid(pb, g);
put_le64(pb, 24);
return pos;
}
/* update header size */
static void end_header(ByteIOContext *pb, INT64 pos)
{
INT64 pos1;
pos1 = url_ftell(pb);
url_fseek(pb, pos + 16, SEEK_SET);
put_le64(pb, pos1 - pos);
url_fseek(pb, pos1, SEEK_SET);
}
/* write an asf chunk (only used in streaming case) */
static void put_chunk(AVFormatContext *s, int type, int payload_length)
{
ASFContext *asf = s->priv_data;
ByteIOContext *pb = &s->pb;
int length;
length = payload_length + 8;
put_le16(pb, type);
put_le16(pb, length);
put_le32(pb, asf->seqno);
put_le16(pb, 0); /* unknown bytes */
put_le16(pb, length);
asf->seqno++;
}
/* convert from unix to windows time */
static INT64 unix_to_file_time(int ti)
{
INT64 t;
t = ti * INT64_C(10000000);
t += INT64_C(116444736000000000);
return t;
}
/* write the header (used two times if non streamed) */
static int asf_write_header1(AVFormatContext *s, INT64 file_size, INT64 data_chunk_size)
{
ASFContext *asf = s->priv_data;
ByteIOContext *pb = &s->pb;
int header_size, n, extra_size, extra_size2, wav_extra_size, file_time;
int has_title;
AVCodecContext *enc;
INT64 header_offset, cur_pos, hpos;
has_title = (s->title[0] != '\0');
if (!url_is_streamed(&s->pb)) {
put_guid(pb, &asf_header);
put_le64(pb, 0); /* header length, will be patched after */
put_le32(pb, 3 + has_title + s->nb_streams); /* number of chunks in header */
put_byte(pb, 1); /* ??? */
put_byte(pb, 2); /* ??? */
} else {
put_chunk(s, 0x4824, 0); /* start of stream (length will be patched later) */
}
/* file header */
header_offset = url_ftell(pb);
hpos = put_header(pb, &file_header);
put_guid(pb, &my_guid);
put_le64(pb, file_size);
file_time = 0;
put_le64(pb, unix_to_file_time(file_time));
put_le64(pb, asf->nb_packets); /* number of packets */
put_le64(pb, asf->duration); /* end time stamp (in 100ns units) */
put_le64(pb, asf->duration); /* duration (in 100ns units) */
put_le32(pb, 0); /* start time stamp */
put_le32(pb, 0); /* ??? */
put_le32(pb, 0); /* ??? */
put_le32(pb, asf->packet_size); /* packet size */
put_le32(pb, asf->packet_size); /* packet size */
put_le32(pb, 80 * asf->packet_size); /* frame_size ??? */
end_header(pb, hpos);
/* unknown headers */
hpos = put_header(pb, &head1_guid);
put_guid(pb, &head2_guid);
put_le32(pb, 6);
put_le16(pb, 0);
end_header(pb, hpos);
/* title and other infos */
if (has_title) {
hpos = put_header(pb, &comment_header);
put_le16(pb, 2 * (strlen(s->title) + 1));
put_le16(pb, 2 * (strlen(s->author) + 1));
put_le16(pb, 2 * (strlen(s->copyright) + 1));
put_le16(pb, 2 * (strlen(s->comment) + 1));
put_le16(pb, 0);
put_str16_nolen(pb, s->title);
put_str16_nolen(pb, s->author);
put_str16_nolen(pb, s->copyright);
put_str16_nolen(pb, s->comment);
end_header(pb, hpos);
}
/* stream headers */
for(n=0;n<s->nb_streams;n++) {
enc = &s->streams[n]->codec;
asf->streams[n].num = n + 1;
asf->streams[n].seq = 0;
switch(enc->codec_type) {
case CODEC_TYPE_AUDIO:
wav_extra_size = 0;
extra_size = 18 + wav_extra_size;
extra_size2 = 0;
break;
default:
case CODEC_TYPE_VIDEO:
wav_extra_size = 0;
extra_size = 0x33;
extra_size2 = 0;
break;
}
hpos = put_header(pb, &stream_header);
if (enc->codec_type == CODEC_TYPE_AUDIO) {
put_guid(pb, &audio_stream);
put_guid(pb, &audio_conceal_none);
} else {
put_guid(pb, &video_stream);
put_guid(pb, &video_conceal_none);
}
put_le64(pb, 0); /* ??? */
put_le32(pb, extra_size); /* wav header len */
put_le32(pb, extra_size2); /* additional data len */
put_le16(pb, n + 1); /* stream number */
put_le32(pb, 0); /* ??? */
if (enc->codec_type == CODEC_TYPE_AUDIO) {
/* WAVEFORMATEX header */
if (put_wav_header(pb, enc) < 0)
return -1;
} else {
put_le32(pb, enc->width);
put_le32(pb, enc->height);
put_byte(pb, 2); /* ??? */
put_le16(pb, 40); /* size */
/* BITMAPINFOHEADER header */
put_bmp_header(pb, enc);
}
end_header(pb, hpos);
}
/* media comments */
hpos = put_header(pb, &codec_comment_header);
put_guid(pb, &codec_comment1_header);
put_le32(pb, s->nb_streams);
for(n=0;n<s->nb_streams;n++) {
enc = &s->streams[n]->codec;
put_le16(pb, asf->streams[n].num);
put_str16(pb, enc->codec_name);
put_le16(pb, 0); /* no parameters */
/* id */
if (enc->codec_type == CODEC_TYPE_AUDIO) {
put_le16(pb, 2);
put_le16(pb, codec_get_tag(codec_wav_tags, enc->codec_id));
} else {
put_le16(pb, 4);
put_le32(pb, codec_get_tag(codec_bmp_tags, enc->codec_id));
}
}
end_header(pb, hpos);
/* patch the header size fields */
cur_pos = url_ftell(pb);
header_size = cur_pos - header_offset;
if (!url_is_streamed(&s->pb)) {
header_size += 24 + 6;
url_fseek(pb, header_offset - 14, SEEK_SET);
put_le64(pb, header_size);
} else {
header_size += 8 + 50;
url_fseek(pb, header_offset - 10, SEEK_SET);
put_le16(pb, header_size);
url_fseek(pb, header_offset - 2, SEEK_SET);
put_le16(pb, header_size);
}
url_fseek(pb, cur_pos, SEEK_SET);
/* movie chunk, followed by packets of packet_size */
asf->data_offset = cur_pos;
put_guid(pb, &data_header);
put_le64(pb, data_chunk_size);
put_guid(pb, &my_guid);
put_le64(pb, asf->nb_packets); /* nb packets */
put_byte(pb, 1); /* ??? */
put_byte(pb, 1); /* ??? */
return 0;
}
static int asf_write_header(AVFormatContext *s)
{
ASFContext *asf;
asf = av_mallocz(sizeof(ASFContext));
if (!asf)
return -1;
s->priv_data = asf;
asf->packet_size = PACKET_SIZE;
asf->nb_packets = 0;
if (asf_write_header1(s, 0, 24) < 0) {
free(asf);
return -1;
}
put_flush_packet(&s->pb);
asf->packet_nb_frames = 0;
asf->packet_timestamp_start = -1;
asf->packet_timestamp_end = -1;
asf->packet_size_left = asf->packet_size - PACKET_HEADER_SIZE;
init_put_byte(&asf->pb, asf->packet_buf, asf->packet_size, 1,
NULL, NULL, NULL, NULL);
return 0;
}
/* write a fixed size packet */
static void put_packet(AVFormatContext *s,
unsigned int timestamp, unsigned int duration,
int nb_frames, int padsize)
{
ASFContext *asf = s->priv_data;
ByteIOContext *pb = &s->pb;
int flags;
if (url_is_streamed(&s->pb)) {
put_chunk(s, 0x4424, asf->packet_size);
}
put_byte(pb, 0x82);
put_le16(pb, 0);
flags = 0x01; /* nb segments present */
if (padsize > 0) {
if (padsize < 256)
flags |= 0x08;
else
flags |= 0x10;
}
put_byte(pb, flags); /* flags */
put_byte(pb, 0x5d);
if (flags & 0x10)
put_le16(pb, padsize);
if (flags & 0x08)
put_byte(pb, padsize);
put_le32(pb, timestamp);
put_le16(pb, duration);
put_byte(pb, nb_frames | 0x80);
}
static void flush_packet(AVFormatContext *s)
{
ASFContext *asf = s->priv_data;
int hdr_size, ptr;
put_packet(s, asf->packet_timestamp_start,
asf->packet_timestamp_end - asf->packet_timestamp_start,
asf->packet_nb_frames, asf->packet_size_left);
/* compute padding */
hdr_size = PACKET_HEADER_SIZE;
if (asf->packet_size_left > 0) {
/* if padding needed, don't forget to count the
padding byte in the header size */
hdr_size++;
asf->packet_size_left--;
/* XXX: I do not test again exact limit to avoid boundary problems */
if (asf->packet_size_left > 200) {
hdr_size++;
asf->packet_size_left--;
}
}
ptr = asf->packet_size - PACKET_HEADER_SIZE - asf->packet_size_left;
memset(asf->packet_buf + ptr, 0, asf->packet_size_left);
put_buffer(&s->pb, asf->packet_buf, asf->packet_size - hdr_size);
put_flush_packet(&s->pb);
asf->nb_packets++;
asf->packet_nb_frames = 0;
asf->packet_timestamp_start = -1;
asf->packet_timestamp_end = -1;
asf->packet_size_left = asf->packet_size - PACKET_HEADER_SIZE;
init_put_byte(&asf->pb, asf->packet_buf, asf->packet_size, 1,
NULL, NULL, NULL, NULL);
}
static void put_frame_header(AVFormatContext *s, ASFStream *stream, int timestamp,
int payload_size, int frag_offset, int frag_len)
{
ASFContext *asf = s->priv_data;
ByteIOContext *pb = &asf->pb;
int val;
val = stream->num;
if (s->streams[val - 1]->codec.key_frame)
val |= 0x80;
put_byte(pb, val);
put_byte(pb, stream->seq);
put_le32(pb, frag_offset); /* fragment offset */
put_byte(pb, 0x08); /* flags */
put_le32(pb, payload_size);
put_le32(pb, timestamp);
put_le16(pb, frag_len);
}
/* Output a frame. We suppose that payload_size <= PACKET_SIZE.
It is there that you understand that the ASF format is really
crap. They have misread the MPEG Systems spec !
*/
static void put_frame(AVFormatContext *s, ASFStream *stream, int timestamp,
UINT8 *buf, int payload_size)
{
ASFContext *asf = s->priv_data;
int frag_pos, frag_len, frag_len1;
frag_pos = 0;
while (frag_pos < payload_size) {
frag_len = payload_size - frag_pos;
frag_len1 = asf->packet_size_left - FRAME_HEADER_SIZE;
if (frag_len1 > 0) {
if (frag_len > frag_len1)
frag_len = frag_len1;
put_frame_header(s, stream, timestamp, payload_size, frag_pos, frag_len);
put_buffer(&asf->pb, buf, frag_len);
asf->packet_size_left -= (frag_len + FRAME_HEADER_SIZE);
asf->packet_timestamp_end = timestamp;
if (asf->packet_timestamp_start == -1)
asf->packet_timestamp_start = timestamp;
asf->packet_nb_frames++;
} else {
frag_len = 0;
}
frag_pos += frag_len;
buf += frag_len;
/* output the frame if filled */
if (asf->packet_size_left <= FRAME_HEADER_SIZE)
flush_packet(s);
}
stream->seq++;
}
static int asf_write_packet(AVFormatContext *s, int stream_index,
UINT8 *buf, int size)
{
ASFContext *asf = s->priv_data;
int timestamp;
INT64 duration;
AVCodecContext *codec;
codec = &s->streams[stream_index]->codec;
if (codec->codec_type == CODEC_TYPE_AUDIO) {
timestamp = (int)((float)codec->frame_number * codec->frame_size * 1000.0 /
codec->sample_rate);
duration = (codec->frame_number * codec->frame_size * INT64_C(10000000)) /
codec->sample_rate;
} else {
timestamp = (int)((float)codec->frame_number * 1000.0 * FRAME_RATE_BASE /
codec->frame_rate);
duration = codec->frame_number *
((INT64_C(10000000) * FRAME_RATE_BASE) / codec->frame_rate);
}
if (duration > asf->duration)
asf->duration = duration;
put_frame(s, &asf->streams[stream_index], (int)timestamp, buf, size);
return 0;
}
static int asf_write_trailer(AVFormatContext *s)
{
ASFContext *asf = s->priv_data;
INT64 file_size;
/* flush the current packet */
if (asf->pb.buf_ptr > asf->pb.buffer)
flush_packet(s);
if (url_is_streamed(&s->pb)) {
put_chunk(s, 0x4524, 0); /* end of stream */
} else {
/* rewrite an updated header */
file_size = url_ftell(&s->pb);
url_fseek(&s->pb, 0, SEEK_SET);
asf_write_header1(s, file_size, file_size - asf->data_offset);
}
put_flush_packet(&s->pb);
free(asf);
return 0;
}
/**********************************/
/* decoding */
//#define DEBUG
#ifdef DEBUG
static void print_guid(const GUID *g)
{
int i;
printf("0x%08x, 0x%04x, 0x%04x, {", g->v1, g->v2, g->v3);
for(i=0;i<8;i++)
printf(" 0x%02x,", g->v4[i]);
printf("}\n");
}
#endif
static void get_guid(ByteIOContext *s, GUID *g)
{
int i;
g->v1 = get_le32(s);
g->v2 = get_le16(s);
g->v3 = get_le16(s);
for(i=0;i<8;i++)
g->v4[i] = get_byte(s);
}
#if 0
static void get_str16(ByteIOContext *pb, char *buf, int buf_size)
{
int len, c;
char *q;
len = get_le16(pb);
q = buf;
while (len > 0) {
c = get_le16(pb);
if ((q - buf) < buf_size - 1)
*q++ = c;
len--;
}
*q = '\0';
}
#endif
static void get_str16_nolen(ByteIOContext *pb, int len, char *buf, int buf_size)
{
int c;
char *q;
q = buf;
while (len > 0) {
c = get_le16(pb);
if ((q - buf) < buf_size - 1)
*q++ = c;
len-=2;
}
*q = '\0';
}
static int asf_read_header(AVFormatContext *s, AVFormatParameters *ap)
{
ASFContext *asf;
GUID g;
ByteIOContext *pb = &s->pb;
AVStream *st;
ASFStream *asf_st;
int size, i, bps;
INT64 gsize;
asf = av_mallocz(sizeof(ASFContext));
if (!asf)
return -1;
s->priv_data = asf;
get_guid(pb, &g);
if (memcmp(&g, &asf_header, sizeof(GUID)))
goto fail;
get_le64(pb);
get_le32(pb);
get_byte(pb);
get_byte(pb);
for(;;) {
get_guid(pb, &g);
gsize = get_le64(pb);
#ifdef DEBUG
printf("%08Lx: ", url_ftell(pb) - 24);
print_guid(&g);
printf(" size=0x%Lx\n", gsize);
#endif
if (gsize < 24)
goto fail;
if (!memcmp(&g, &file_header, sizeof(GUID))) {
get_guid(pb, &g);
get_le64(pb); /* file size */
get_le64(pb); /* file time */
get_le64(pb); /* nb_packets */
get_le64(pb); /* length 0 in us */
get_le64(pb); /* length 1 in us */
get_le32(pb);
get_le32(pb);
get_le32(pb);
asf->packet_size = get_le32(pb);
get_le32(pb);
get_le32(pb);
} else if (!memcmp(&g, &stream_header, sizeof(GUID))) {
int type, id, total_size;
unsigned int tag1;
INT64 pos1, pos2;
pos1 = url_ftell(pb);
st = av_mallocz(sizeof(AVStream));
if (!st)
goto fail;
s->streams[s->nb_streams++] = st;
asf_st = av_mallocz(sizeof(ASFStream));
if (!asf_st)
goto fail;
st->priv_data = asf_st;
get_guid(pb, &g);
if (!memcmp(&g, &audio_stream, sizeof(GUID))) {
type = CODEC_TYPE_AUDIO;
} else if (!memcmp(&g, &video_stream, sizeof(GUID))) {
type = CODEC_TYPE_VIDEO;
} else {
goto fail;
}
get_guid(pb, &g);
total_size = get_le64(pb);
get_le32(pb);
get_le32(pb);
st->id = get_le16(pb); /* stream id */
get_le32(pb);
st->codec.codec_type = type;
if (type == CODEC_TYPE_AUDIO) {
id = get_le16(pb);
st->codec.codec_tag = id;
st->codec.channels = get_le16(pb);
st->codec.sample_rate = get_le32(pb);
st->codec.bit_rate = get_le32(pb) * 8;
get_le16(pb); /* block align */
bps = get_le16(pb); /* bits per sample */
st->codec.codec_id = wav_codec_get_id(id, bps);
size = get_le16(pb);
url_fskip(pb, size);
} else {
get_le32(pb);
get_le32(pb);
get_byte(pb);
size = get_le16(pb); /* size */
get_le32(pb); /* size */
st->codec.width = get_le32(pb);
st->codec.height = get_le32(pb);
st->codec.frame_rate = 25 * FRAME_RATE_BASE; /* XXX: find it */
get_le16(pb); /* panes */
get_le16(pb); /* depth */
tag1 = get_le32(pb);
st->codec.codec_tag = tag1;
st->codec.codec_id = codec_get_id(codec_bmp_tags, tag1);
url_fskip(pb, size - 5 * 4);
}
pos2 = url_ftell(pb);
url_fskip(pb, gsize - (pos2 - pos1 + 24));
} else if (!memcmp(&g, &data_header, sizeof(GUID))) {
break;
} else if (!memcmp(&g, &comment_header, sizeof(GUID))) {
int len1, len2, len3, len4, len5;
len1 = get_le16(pb);
len2 = get_le16(pb);
len3 = get_le16(pb);
len4 = get_le16(pb);
len5 = get_le16(pb);
get_str16_nolen(pb, len1, s->title, sizeof(s->title));
get_str16_nolen(pb, len2, s->author, sizeof(s->author));
get_str16_nolen(pb, len3, s->copyright, sizeof(s->copyright));
get_str16_nolen(pb, len4, s->comment, sizeof(s->comment));
url_fskip(pb, len5);
#if 0
} else if (!memcmp(&g, &head1_guid, sizeof(GUID))) {
int v1, v2;
get_guid(pb, &g);
v1 = get_le32(pb);
v2 = get_le16(pb);
} else if (!memcmp(&g, &codec_comment_header, sizeof(GUID))) {
int len, v1, n, num;
char str[256], *q;
char tag[16];
get_guid(pb, &g);
print_guid(&g);
n = get_le32(pb);
for(i=0;i<n;i++) {
num = get_le16(pb); /* stream number */
get_str16(pb, str, sizeof(str));
get_str16(pb, str, sizeof(str));
len = get_le16(pb);
q = tag;
while (len > 0) {
v1 = get_byte(pb);
if ((q - tag) < sizeof(tag) - 1)
*q++ = v1;
len--;
}
*q = '\0';
}
#endif
} else if (url_feof(pb)) {
goto fail;
} else {
url_fseek(pb, gsize - 24, SEEK_CUR);
}
}
get_guid(pb, &g);
get_le64(pb);
get_byte(pb);
get_byte(pb);
asf->packet_size_left = 0;
return 0;
fail:
for(i=0;i<s->nb_streams;i++) {
AVStream *st = s->streams[i];
if (st)
free(st->priv_data);
free(st);
}
free(asf);
return -1;
}
static int asf_get_packet(AVFormatContext *s)
{
ASFContext *asf = s->priv_data;
ByteIOContext *pb = &s->pb;
int c, flags, timestamp, hdr_size;
hdr_size = 12;
c = get_byte(pb);
if (c != 0x82)
return -EIO;
get_le16(pb);
flags = get_byte(pb);
get_byte(pb);
asf->packet_padsize = 0;
if (flags & 0x10) {
asf->packet_padsize = get_le16(pb);
hdr_size += 2;
} else if (flags & 0x08) {
asf->packet_padsize = get_byte(pb);
hdr_size++;
}
timestamp = get_le32(pb);
get_le16(pb); /* duration */
get_byte(pb); /* nb_frames */
#ifdef DEBUG
printf("packet: size=%d padsize=%d\n", asf->packet_size, asf->packet_padsize);
#endif
asf->packet_size_left = asf->packet_size - hdr_size;
return 0;
}
static int asf_read_packet(AVFormatContext *s, AVPacket *pkt)
{
ASFContext *asf = s->priv_data;
AVStream *st;
ASFStream *asf_st;
ByteIOContext *pb = &s->pb;
int ret, num, seq, frag_offset, payload_size, frag_len;
int timestamp, i;
for(;;) {
if (asf->packet_size_left < FRAME_HEADER_SIZE ||
asf->packet_size_left <= asf->packet_padsize) {
/* fail safe */
if (asf->packet_size_left)
url_fskip(pb, asf->packet_size_left);
ret = asf_get_packet(s);
if (ret < 0)
return -EIO;
}
/* read frame header */
num = get_byte(pb) & 0x7f;
seq = get_byte(pb);
frag_offset = get_le32(pb);
get_byte(pb); /* flags */
payload_size = get_le32(pb);
timestamp = get_le32(pb);
frag_len = get_le16(pb);
#ifdef DEBUG
printf("num=%d seq=%d totsize=%d frag_off=%d frag_size=%d\n",
num, seq, payload_size, frag_offset, frag_len);
#endif
st = NULL;
for(i=0;i<s->nb_streams;i++) {
st = s->streams[i];
if (st->id == num)
break;
}
asf->packet_size_left -= FRAME_HEADER_SIZE + frag_len;
if (i == s->nb_streams) {
/* unhandled packet (should not happen) */
url_fskip(pb, frag_len);
} else {
asf_st = st->priv_data;
if (asf_st->frag_offset == 0) {
/* new packet */
av_new_packet(&asf_st->pkt, payload_size);
asf_st->seq = seq;
} else {
if (seq == asf_st->seq &&
frag_offset == asf_st->frag_offset) {
/* continuing packet */
} else {
/* cannot continue current packet: free it */
av_free_packet(&asf_st->pkt);
asf_st->frag_offset = 0;
if (frag_offset != 0) {
/* cannot create new packet */
url_fskip(pb, frag_len);
goto next_frame;
} else {
/* create new packet */
av_new_packet(&asf_st->pkt, payload_size);
asf_st->seq = seq;
}
}
}
/* read data */
get_buffer(pb, asf_st->pkt.data + frag_offset, frag_len);
asf_st->frag_offset += frag_len;
/* test if whole packet read */
if (asf_st->frag_offset == asf_st->pkt.size) {
/* return packet */
asf_st->pkt.stream_index = i;
asf_st->frag_offset = 0;
memcpy(pkt, &asf_st->pkt, sizeof(AVPacket));
break;
}
}
next_frame:;
}
return 0;
}
static int asf_read_close(AVFormatContext *s)
{
ASFContext *asf = s->priv_data;
int i;
for(i=0;i<s->nb_streams;i++) {
AVStream *st = s->streams[i];
free(st->priv_data);
}
free(asf);
return 0;
}
AVFormat asf_format = {
"asf",
"asf format",
"application/octet-stream",
"asf,wmv",
CODEC_ID_MP2,
CODEC_ID_MSMPEG4,
asf_write_header,
asf_write_packet,
asf_write_trailer,
asf_read_header,
asf_read_packet,
asf_read_close,
};
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