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FFmpeg/libavformat/nut.c

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/*
* "NUT" Container Format muxer and demuxer (DRAFT-200403??)
* Copyright (c) 2003 Alex Beregszaszi
* Copyright (c) 2004 Michael Niedermayer
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* NUT DRAFT can be found in MPlayer CVS at DOCS/tech/mpcf.txt
*
* AND http://people.fsn.hu/~alex/nut/ (TeX, pdf, ps, dvi, ..)
*
*/
/*
* TODO:
* - seeking
* - index writing
* - index packet reading support
*/
//#define DEBUG 1
#include <limits.h>
#include "avformat.h"
#include "mpegaudio.h"
#include "avi.h"
#undef NDEBUG
#include <assert.h>
//from /dev/random
#define MAIN_STARTCODE (0x7A561F5F04ADULL + (((uint64_t)('N'<<8) + 'M')<<48))
#define STREAM_STARTCODE (0x11405BF2F9DBULL + (((uint64_t)('N'<<8) + 'S')<<48))
#define KEYFRAME_STARTCODE (0xE4ADEECA4569ULL + (((uint64_t)('N'<<8) + 'K')<<48))
#define INDEX_STARTCODE (0xDD672F23E64EULL + (((uint64_t)('N'<<8) + 'X')<<48))
#define INFO_STARTCODE (0xAB68B596BA78ULL + (((uint64_t)('N'<<8) + 'I')<<48))
#define MAX_TYPE1_DISTANCE (1024*16-1)
#define MAX_TYPE2_DISTANCE (1024*64-1)
#define MAX_SIZE_LRU 2
#define MAX_PTS_LRU 3
#define FLAG_FRAME_TYPE 1
#define FLAG_DATA_SIZE 2
#define FLAG_PTS 16
#define FLAG_FULL_PTS 4
#define FLAG_KEY_FRAME 32
#define FLAG_PRED_KEY_FRAME 64
typedef struct {
uint8_t flags;
uint8_t stream_id_plus1;
uint8_t size_mul;
uint8_t size_lsb;
} FrameCode;
typedef struct {
int last_key_frame;
int msb_timestamp_shift;
int rate_num;
int rate_den;
int64_t last_pts;
int64_t last_full_pts;
int lru_pts_delta[MAX_PTS_LRU];
int lru_size[MAX_SIZE_LRU];
int initial_pts_predictor[MAX_PTS_LRU];
int initial_size_predictor[MAX_SIZE_LRU];
} StreamContext;
typedef struct {
AVFormatContext *avf;
int64_t packet_start;
int64_t last_packet_start;
int written_packet_size;
int64_t packet_size_pos;
int64_t last_frame_start[3];
FrameCode frame_code[256];
int stream_count;
uint64_t next_startcode; ///< stores the next startcode if it has alraedy been parsed but the stream isnt seekable
StreamContext *stream;
} NUTContext;
static char *info_table[][2]={
{NULL , NULL }, // end
{NULL , NULL },
{NULL , "UTF8"},
{NULL , "v"},
{NULL , "s"},
{"StreamId" , "v"},
{"SegmentId" , "v"},
{"StartTimestamp" , "v"},
{"EndTimestamp" , "v"},
{"Author" , "UTF8"},
{"Title" , "UTF8"},
{"Description" , "UTF8"},
{"Copyright" , "UTF8"},
{"Encoder" , "UTF8"},
{"Keyword" , "UTF8"},
{"Cover" , "JPEG"},
{"Cover" , "PNG"},
};
static void update_lru(int *lru, int current, int count){
int i;
for(i=0; i<count-1; i++){
if(lru[i] == current)
break;
}
for(; i; i--){
lru[i]= lru[i-1];
}
lru[0]= current;
}
static void update(NUTContext *nut, int stream_index, int64_t frame_start, int frame_type, int frame_code, int key_frame, int size, int64_t pts){
StreamContext *stream= &nut->stream[stream_index];
const int flags=nut->frame_code[frame_code].flags;
stream->last_key_frame= key_frame;
nut->last_frame_start[ frame_type ]= frame_start;
if(frame_type == 0)
update_lru(stream->lru_pts_delta, pts - stream->last_pts, 3);
update_lru(stream->lru_size, size, 2);
stream->last_pts= pts;
if((flags & FLAG_PTS) && (flags & FLAG_FULL_PTS))
stream->last_full_pts= pts;
}
static void reset(AVFormatContext *s/*, int frame_type*/){
NUTContext *nut = s->priv_data;
int i;
for(i=0; i<s->nb_streams; i++){
StreamContext *stream= &nut->stream[i];
stream->last_key_frame= 1;
memcpy(stream->lru_pts_delta, stream->initial_pts_predictor, sizeof(int)*MAX_PTS_LRU);
memcpy(stream->lru_size, stream->initial_size_predictor, sizeof(int)*MAX_SIZE_LRU);
}
}
static void build_frame_code(AVFormatContext *s){
NUTContext *nut = s->priv_data;
int key_frame, frame_type, full_pts, index, pred, stream_id;
int start=0;
int end= 255;
int keyframe_0_esc= s->nb_streams > 2;
if(keyframe_0_esc){
/* keyframe = 0 escapes, 3 codes */
for(frame_type=0; frame_type<2; frame_type++){
for(full_pts=frame_type; full_pts<2; full_pts++){
FrameCode *ft= &nut->frame_code[start];
ft->flags= FLAG_FRAME_TYPE*frame_type + FLAG_FULL_PTS*full_pts;
ft->flags|= FLAG_DATA_SIZE | FLAG_PTS;
ft->stream_id_plus1= 0;
ft->size_mul=1;
start++;
}
}
}
for(stream_id= 0; stream_id<s->nb_streams; stream_id++){
int start2= start + (end-start)*stream_id / s->nb_streams;
int end2 = start + (end-start)*(stream_id+1) / s->nb_streams;
AVCodecContext *codec = &s->streams[stream_id]->codec;
int is_audio= codec->codec_type == CODEC_TYPE_AUDIO;
int intra_only= /*codec->intra_only || */is_audio;
int pred_count;
for(key_frame=0; key_frame<2; key_frame++){
if(intra_only && keyframe_0_esc && key_frame==0)
continue;
for(frame_type=0; frame_type<2; frame_type++){
for(full_pts=frame_type; full_pts<2; full_pts++){
FrameCode *ft= &nut->frame_code[start2];
ft->flags= FLAG_FRAME_TYPE*frame_type + FLAG_FULL_PTS*full_pts + FLAG_KEY_FRAME*key_frame;
ft->flags|= FLAG_DATA_SIZE | FLAG_PTS;
ft->stream_id_plus1= stream_id + 1;
ft->size_mul=1;
start2++;
}
}
}
key_frame= intra_only;
#if 1
if(is_audio){
int frame_bytes= codec->frame_size*(int64_t)codec->bit_rate / (8*codec->sample_rate);
for(pred=0; pred<MAX_SIZE_LRU; pred++){
for(frame_type=0; frame_type<1; frame_type++){
FrameCode *ft= &nut->frame_code[start2];
ft->flags= FLAG_KEY_FRAME*key_frame + (FLAG_FULL_PTS+FLAG_PTS+FLAG_FRAME_TYPE)*frame_type;
ft->stream_id_plus1= stream_id + 1;
ft->size_mul=1;
ft->size_lsb=1 + pred;
start2++;
}
nut->stream[stream_id].initial_size_predictor[pred]= frame_bytes + pred;
}
}else{
FrameCode *ft= &nut->frame_code[start2];
ft->flags= FLAG_KEY_FRAME | FLAG_DATA_SIZE;
ft->stream_id_plus1= stream_id + 1;
ft->size_mul=1;
start2++;
}
#endif
pred_count= 2 + codec->has_b_frames + (codec->codec_id == CODEC_ID_VORBIS);
for(pred=0; pred<pred_count; pred++){
int start3= start2 + (end2-start2)*pred / pred_count;
int end3 = start2 + (end2-start2)*(pred+1) / pred_count;
for(index=start3; index<end3; index++){
FrameCode *ft= &nut->frame_code[index];
ft->flags= FLAG_KEY_FRAME*key_frame + pred*4;
ft->flags|= FLAG_DATA_SIZE;
ft->stream_id_plus1= stream_id + 1;
//FIXME use single byte size and pred from last
ft->size_mul= end3-start3;
ft->size_lsb= index - start3;
}
nut->stream[stream_id].initial_pts_predictor[pred]= pred+1;
}
}
memmove(&nut->frame_code['N'+1], &nut->frame_code['N'], sizeof(FrameCode)*(255-'N'));
nut->frame_code['N'].flags= 1;
}
static uint64_t get_v(ByteIOContext *bc)
{
uint64_t val = 0;
for(;;)
{
int tmp = get_byte(bc);
if (tmp&0x80)
val= (val<<7) + tmp - 0x80;
else
return (val<<7) + tmp;
}
return -1;
}
static int get_str(ByteIOContext *bc, char *string, int maxlen){
int len= get_v(bc);
if(len && maxlen)
get_buffer(bc, string, FFMIN(len, maxlen));
while(len > maxlen){
get_byte(bc);
len--;
}
if(maxlen)
string[FFMIN(len, maxlen-1)]= 0;
if(maxlen == len)
return -1;
else
return 0;
}
static int get_packetheader(NUTContext *nut, ByteIOContext *bc, int prefix_length, int calculate_checksum)
{
int64_t start, size, last_size;
start= url_ftell(bc) - prefix_length;
if(start != nut->packet_start + nut->written_packet_size){
av_log(nut->avf, AV_LOG_ERROR, "get_packetheader called at weird position\n");
if(prefix_length<8)
return -1;
}
init_checksum(bc, calculate_checksum ? update_adler32 : NULL, 0);
size= get_v(bc);
last_size= get_v(bc);
if(nut->written_packet_size != last_size){
av_log(nut->avf, AV_LOG_ERROR, "packet size missmatch %d != %lld at %lld\n", nut->written_packet_size, last_size, start);
if(prefix_length<8)
return -1;
}
nut->last_packet_start = nut->packet_start;
nut->packet_start = start;
nut->written_packet_size= size;
return size;
}
static int check_checksum(ByteIOContext *bc){
unsigned long checksum= get_checksum(bc);
return checksum != get_be32(bc);
}
/**
*
*/
static int get_length(uint64_t val){
int i;
for (i=7; ; i+=7)
if ((val>>i) == 0)
return i;
return 7; //not reached
}
static uint64_t find_any_startcode(ByteIOContext *bc, int64_t pos){
uint64_t state=0;
if(pos >= 0)
url_fseek(bc, pos, SEEK_SET); //note, this may fail if the stream isnt seekable, but that shouldnt matter, as in this case we simply start where we are currently
while(!url_feof(bc)){
state= (state<<8) | get_byte(bc);
if((state>>56) != 'N')
continue;
switch(state){
case MAIN_STARTCODE:
case STREAM_STARTCODE:
case KEYFRAME_STARTCODE:
case INFO_STARTCODE:
case INDEX_STARTCODE:
return state;
}
}
av_log(NULL, AV_LOG_DEBUG, "searched until %lld\n", url_ftell(bc));
return 0;
}
static int find_startcode(ByteIOContext *bc, uint64_t code, int64_t pos){
for(;;){
uint64_t startcode= find_any_startcode(bc, pos);
if(startcode == code)
return 0;
else if(startcode == 0)
return -1;
pos=-1;
}
}
#ifdef CONFIG_ENCODERS
static int put_v(ByteIOContext *bc, uint64_t val)
{
int i;
val &= 0x7FFFFFFFFFFFFFFFULL; // FIXME can only encode upto 63 bits currently
i= get_length(val);
for (i-=7; i>0; i-=7){
put_byte(bc, 0x80 | (val>>i));
}
put_byte(bc, val&0x7f);
return 0;
}
static int put_str(ByteIOContext *bc, const char *string){
int len= strlen(string);
put_v(bc, len);
put_buffer(bc, string, len);
return 0;
}
static int put_packetheader(NUTContext *nut, ByteIOContext *bc, int max_size, int calculate_checksum)
{
put_flush_packet(bc);
nut->last_packet_start= nut->packet_start;
nut->packet_start+= nut->written_packet_size;
nut->packet_size_pos = url_ftell(bc);
nut->written_packet_size = max_size;
if(calculate_checksum)
init_checksum(bc, update_adler32, 0);
/* packet header */
put_v(bc, nut->written_packet_size); /* forward ptr */
put_v(bc, nut->packet_start - nut->last_packet_start); /* backward ptr */
return 0;
}
static int update_packetheader(NUTContext *nut, ByteIOContext *bc, int additional_size, int calculate_checksum){
int64_t start= nut->packet_start;
int64_t cur= url_ftell(bc);
int size= cur - start + additional_size;
if(calculate_checksum)
size += 4;
if(size != nut->written_packet_size){
int i;
assert( size <= nut->written_packet_size );
url_fseek(bc, nut->packet_size_pos, SEEK_SET);
for(i=get_length(size); i < get_length(nut->written_packet_size); i+=7)
put_byte(bc, 0x80);
put_v(bc, size);
url_fseek(bc, cur, SEEK_SET);
nut->written_packet_size= size; //FIXME may fail if multiple updates with differing sizes, as get_length may differ
if(calculate_checksum)
put_be32(bc, get_checksum(bc));
}
return 0;
}
static int nut_write_header(AVFormatContext *s)
{
NUTContext *nut = s->priv_data;
ByteIOContext *bc = &s->pb;
AVCodecContext *codec;
int i, j;
nut->avf= s;
nut->stream =
av_mallocz(sizeof(StreamContext)*s->nb_streams);
av_set_pts_info(s, 60, 1, AV_TIME_BASE);
/* main header */
put_be64(bc, MAIN_STARTCODE);
put_packetheader(nut, bc, 120+5*256, 1);
put_v(bc, 1); /* version */
put_v(bc, s->nb_streams);
put_v(bc, 3);
build_frame_code(s);
assert(nut->frame_code['N'].flags == 1);
for(i=0; i<256;){
int tmp_flags = nut->frame_code[i].flags;
int tmp_stream= nut->frame_code[i].stream_id_plus1;
int tmp_mul = nut->frame_code[i].size_mul;
int tmp_size = nut->frame_code[i].size_lsb;
put_v(bc, tmp_flags);
put_v(bc, tmp_stream);
put_v(bc, tmp_mul);
put_v(bc, tmp_size);
for(j=0; i<256; j++,i++){
if(nut->frame_code[i].flags != tmp_flags ) break;
if(nut->frame_code[i].stream_id_plus1 != tmp_stream) break;
if(nut->frame_code[i].size_mul != tmp_mul ) break;
if(nut->frame_code[i].size_lsb != tmp_size ) break;
if(++tmp_size >= tmp_mul){
tmp_size=0;
tmp_stream++;
}
}
put_v(bc, j);
}
update_packetheader(nut, bc, 0, 1);
/* stream headers */
for (i = 0; i < s->nb_streams; i++)
{
int nom, denom, gcd;
codec = &s->streams[i]->codec;
put_be64(bc, STREAM_STARTCODE);
put_packetheader(nut, bc, 120 + codec->extradata_size, 1);
put_v(bc, i /*s->streams[i]->index*/);
put_v(bc, (codec->codec_type == CODEC_TYPE_AUDIO) ? 32 : 0);
if (codec->codec_tag)
put_v(bc, codec->codec_tag);
else if (codec->codec_type == CODEC_TYPE_VIDEO)
{
put_v(bc, codec_get_bmp_tag(codec->codec_id));
}
else if (codec->codec_type == CODEC_TYPE_AUDIO)
{
put_v(bc, codec_get_wav_tag(codec->codec_id));
}
else
put_v(bc, 0);
if (codec->codec_type == CODEC_TYPE_VIDEO)
{
nom = codec->frame_rate;
denom = codec->frame_rate_base;
}
else
{
nom = codec->sample_rate;
if(codec->frame_size>0)
denom= codec->frame_size;
else
denom= 1; //unlucky
}
gcd= ff_gcd(nom, denom);
nom /= gcd;
denom /= gcd;
nut->stream[i].rate_num= nom;
nut->stream[i].rate_den= denom;
put_v(bc, codec->bit_rate);
put_v(bc, 0); /* no language code */
put_v(bc, nom);
put_v(bc, denom);
if(nom / denom < 1000)
nut->stream[i].msb_timestamp_shift = 7;
else
nut->stream[i].msb_timestamp_shift = 14;
put_v(bc, nut->stream[i].msb_timestamp_shift);
for(j=0; j<3; j++)
put_v(bc, nut->stream[i].initial_pts_predictor[j]);
for(j=0; j<2; j++)
put_v(bc, nut->stream[i].initial_size_predictor[j]);
put_byte(bc, 0); /* flags: 0x1 - fixed_fps, 0x2 - index_present */
if(codec->extradata_size){
put_v(bc, 1);
put_v(bc, codec->extradata_size);
put_buffer(bc, codec->extradata, codec->extradata_size);
}
put_v(bc, 0); /* end of codec specific headers */
switch(codec->codec_type)
{
case CODEC_TYPE_AUDIO:
put_v(bc, (codec->sample_rate * denom) / nom);
put_v(bc, codec->channels);
break;
case CODEC_TYPE_VIDEO:
put_v(bc, codec->width);
put_v(bc, codec->height);
put_v(bc, codec->sample_aspect_ratio.num);
put_v(bc, codec->sample_aspect_ratio.den);
put_v(bc, 0); /* csp type -- unknown */
break;
default:
break;
}
update_packetheader(nut, bc, 0, 1);
}
/* info header */
put_be64(bc, INFO_STARTCODE);
put_packetheader(nut, bc, 30+strlen(s->author)+strlen(s->title)+
strlen(s->comment)+strlen(s->copyright)+strlen(LIBAVFORMAT_IDENT), 1);
if (s->author[0])
{
put_v(bc, 9); /* type */
put_str(bc, s->author);
}
if (s->title[0])
{
put_v(bc, 10); /* type */
put_str(bc, s->title);
}
if (s->comment[0])
{
put_v(bc, 11); /* type */
put_str(bc, s->comment);
}
if (s->copyright[0])
{
put_v(bc, 12); /* type */
put_str(bc, s->copyright);
}
/* encoder */
put_v(bc, 13); /* type */
put_str(bc, LIBAVFORMAT_IDENT);
put_v(bc, 0); /* eof info */
update_packetheader(nut, bc, 0, 1);
put_flush_packet(bc);
return 0;
}
static int nut_write_packet(AVFormatContext *s, int stream_index,
const uint8_t *buf, int size, int64_t pts)
{
NUTContext *nut = s->priv_data;
StreamContext *stream= &nut->stream[stream_index];
ByteIOContext *bc = &s->pb;
int key_frame = 0, full_pts=0;
AVCodecContext *enc;
int64_t lsb_pts, delta_pts;
int frame_type, best_length, frame_code, flags, i, size_mul, size_lsb;
const int64_t frame_start= url_ftell(bc);
if (stream_index > s->nb_streams)
return 1;
pts= (av_rescale(pts, stream->rate_num, stream->rate_den) + AV_TIME_BASE/2) / AV_TIME_BASE;
enc = &s->streams[stream_index]->codec;
key_frame = enc->coded_frame->key_frame;
delta_pts= pts - stream->last_pts;
frame_type=0;
if(frame_start + size + 20 - FFMAX(nut->last_frame_start[1], nut->last_frame_start[2]) > MAX_TYPE1_DISTANCE)
frame_type=1;
if(key_frame){
if(frame_type==1 && frame_start + size - nut->last_frame_start[2] > MAX_TYPE2_DISTANCE)
frame_type=2;
if(!stream->last_key_frame)
frame_type=2;
}
if(frame_type>0){
update_packetheader(nut, bc, 0, 0);
reset(s);
full_pts=1;
}
//FIXME ensure that the timestamp can be represented by either delta or lsb or full_pts=1
lsb_pts = pts & ((1 << stream->msb_timestamp_shift)-1);
best_length=INT_MAX;
frame_code= -1;
for(i=0; i<256; i++){
int stream_id_plus1= nut->frame_code[i].stream_id_plus1;
int fc_key_frame= stream->last_key_frame;
int length=0;
size_mul= nut->frame_code[i].size_mul;
size_lsb= nut->frame_code[i].size_lsb;
flags= nut->frame_code[i].flags;
if(stream_id_plus1 == 0) length+= get_length(stream_index);
else if(stream_id_plus1 - 1 != stream_index)
continue;
if(flags & FLAG_PRED_KEY_FRAME){
if(flags & FLAG_KEY_FRAME)
fc_key_frame= !fc_key_frame;
}else{
fc_key_frame= !!(flags & FLAG_KEY_FRAME);
}
assert(key_frame==0 || key_frame==1);
if(fc_key_frame != key_frame)
continue;
if((!!(flags & FLAG_FRAME_TYPE)) != (frame_type > 0))
continue;
if(size_mul <= size_lsb){
int p= stream->lru_size[size_lsb - size_mul];
if(p != size)
continue;
}else{
if(size % size_mul != size_lsb)
continue;
if(flags & FLAG_DATA_SIZE)
length += get_length(size / size_mul);
else if(size/size_mul)
continue;
}
if(full_pts != ((flags & FLAG_PTS) && (flags & FLAG_FULL_PTS)))
continue;
if(flags&FLAG_PTS){
if(flags&FLAG_FULL_PTS){
length += get_length(pts);
}else{
length += get_length(lsb_pts);
}
}else{
int delta= stream->lru_pts_delta[(flags & 12)>>2];
if(delta != pts - stream->last_pts)
continue;
assert(frame_type == 0);
}
if(length < best_length){
best_length= length;
frame_code=i;
}
// av_log(s, AV_LOG_DEBUG, "%d %d %d %d %d %d %d %d %d %d\n", key_frame, frame_type, full_pts, size, stream_index, flags, size_mul, size_lsb, stream_id_plus1, length);
}
assert(frame_code != -1);
flags= nut->frame_code[frame_code].flags;
size_mul= nut->frame_code[frame_code].size_mul;
size_lsb= nut->frame_code[frame_code].size_lsb;
#if 0
best_length /= 7;
best_length ++; //frame_code
if(frame_type>0){
best_length += 4; //packet header
if(frame_type>1)
best_length += 8; // startcode
}
av_log(s, AV_LOG_DEBUG, "kf:%d ft:%d pt:%d fc:%2X len:%2d size:%d stream:%d flag:%d mul:%d lsb:%d s+1:%d pts_delta:%d\n", key_frame, frame_type, full_pts ? 2 : ((flags & FLAG_PTS) ? 1 : 0), frame_code, best_length, size, stream_index, flags, size_mul, size_lsb, nut->frame_code[frame_code].stream_id_plus1,(int)(pts - stream->last_pts));
#endif
if (frame_type==2)
put_be64(bc, KEYFRAME_STARTCODE);
put_byte(bc, frame_code);
if(frame_type>0)
put_packetheader(nut, bc, FFMAX(size+20, MAX_TYPE1_DISTANCE), 0);
if(nut->frame_code[frame_code].stream_id_plus1 == 0)
put_v(bc, stream_index);
if (flags & FLAG_PTS){
if (flags & FLAG_FULL_PTS)
put_v(bc, pts);
else
put_v(bc, lsb_pts);
}
if(flags & FLAG_DATA_SIZE)
put_v(bc, size / size_mul);
if(size > MAX_TYPE1_DISTANCE){
assert(frame_type > 0);
update_packetheader(nut, bc, size, 0);
}
put_buffer(bc, buf, size);
update(nut, stream_index, frame_start, frame_type, frame_code, key_frame, size, pts);
return 0;
}
static int nut_write_trailer(AVFormatContext *s)
{
NUTContext *nut = s->priv_data;
ByteIOContext *bc = &s->pb;
update_packetheader(nut, bc, 0, 0);
#if 0
int i;
/* WRITE INDEX */
for (i = 0; s->nb_streams; i++)
{
put_be64(bc, INDEX_STARTCODE);
put_packetheader(nut, bc, 64, 1);
put_v(bc, s->streams[i]->id);
put_v(bc, ...);
update_packetheader(nut, bc, 0, 1);
}
#endif
put_flush_packet(bc);
av_freep(&nut->stream);
return 0;
}
#endif //CONFIG_ENCODERS
static int nut_probe(AVProbeData *p)
{
int i;
uint64_t code;
code = 0xff;
for (i = 0; i < p->buf_size; i++) {
int c = p->buf[i];
code = (code << 8) | c;
if (code == MAIN_STARTCODE)
return AVPROBE_SCORE_MAX;
}
return 0;
}
static int decode_main_header(NUTContext *nut){
AVFormatContext *s= nut->avf;
ByteIOContext *bc = &s->pb;
uint64_t tmp;
int i, j;
get_packetheader(nut, bc, 8, 1);
tmp = get_v(bc);
if (tmp != 1){
av_log(s, AV_LOG_ERROR, "bad version (%Ld)\n", tmp);
return -1;
}
nut->stream_count = get_v(bc);
get_v(bc); //checksum threshold
for(i=0; i<256;){
int tmp_flags = get_v(bc);
int tmp_stream= get_v(bc);
int tmp_mul = get_v(bc);
int tmp_size = get_v(bc);
int count = get_v(bc);
if(count == 0 || i+count > 256){
av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);
return -1;
}
if((tmp_flags & FLAG_FRAME_TYPE) && tmp_flags != 1){
if(tmp_flags & FLAG_PRED_KEY_FRAME){
av_log(s, AV_LOG_ERROR, "keyframe prediction in non 0 frame type\n");
return -1;
}
if(!(tmp_flags & FLAG_PTS) || !(tmp_flags & FLAG_FULL_PTS) ){
av_log(s, AV_LOG_ERROR, "no full pts in non 0 frame type\n");
return -1;
}
}
for(j=0; j<count; j++,i++){
if(tmp_stream > nut->stream_count + 1){
av_log(s, AV_LOG_ERROR, "illegal stream number\n");
return -1;
}
nut->frame_code[i].flags = tmp_flags ;
nut->frame_code[i].stream_id_plus1 = tmp_stream;
nut->frame_code[i].size_mul = tmp_mul ;
nut->frame_code[i].size_lsb = tmp_size ;
if(++tmp_size >= tmp_mul){
tmp_size=0;
tmp_stream++;
}
}
}
if(nut->frame_code['N'].flags != 1){
av_log(s, AV_LOG_ERROR, "illegal frame_code table\n");
return -1;
}
if(check_checksum(bc)){
av_log(s, AV_LOG_ERROR, "Main header checksum missmatch\n");
return -1;
}
return 0;
}
static int decode_stream_header(NUTContext *nut){
AVFormatContext *s= nut->avf;
ByteIOContext *bc = &s->pb;
int class, nom, denom, stream_id, i;
uint64_t tmp;
AVStream *st;
get_packetheader(nut, bc, 8, 1);
stream_id= get_v(bc);
if(stream_id >= nut->stream_count || s->streams[stream_id])
return -1;
st = av_new_stream(s, stream_id);
if (!st)
return AVERROR_NOMEM;
class = get_v(bc);
tmp = get_v(bc);
switch(class)
{
case 0:
st->codec.codec_type = CODEC_TYPE_VIDEO;
st->codec.codec_id = codec_get_bmp_id(tmp);
if (st->codec.codec_id == CODEC_ID_NONE)
av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
break;
case 32:
st->codec.codec_type = CODEC_TYPE_AUDIO;
st->codec.codec_id = codec_get_wav_id(tmp);
if (st->codec.codec_id == CODEC_ID_NONE)
av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
break;
default:
av_log(s, AV_LOG_ERROR, "Unknown stream class (%d)\n", class);
return -1;
}
s->bit_rate += get_v(bc);
get_v(bc); /* language code */
nom = get_v(bc);
denom = get_v(bc);
nut->stream[stream_id].msb_timestamp_shift = get_v(bc);
for(i=0; i<3; i++)
nut->stream[stream_id].initial_pts_predictor[i]= get_v(bc);
for(i=0; i<2; i++)
nut->stream[stream_id].initial_size_predictor[i]= get_v(bc);
get_byte(bc); /* flags */
/* codec specific data headers */
while(get_v(bc) != 0){
st->codec.extradata_size= get_v(bc);
st->codec.extradata= av_mallocz(st->codec.extradata_size);
get_buffer(bc, st->codec.extradata, st->codec.extradata_size);
// url_fskip(bc, get_v(bc));
}
if (class == 0) /* VIDEO */
{
st->codec.width = get_v(bc);
st->codec.height = get_v(bc);
st->codec.sample_aspect_ratio.num= get_v(bc);
st->codec.sample_aspect_ratio.den= get_v(bc);
get_v(bc); /* csp type */
st->codec.frame_rate = nom;
st->codec.frame_rate_base = denom;
}
if (class == 32) /* AUDIO */
{
st->codec.sample_rate = (get_v(bc) * nom) / denom;
st->codec.channels = get_v(bc);
}
if(check_checksum(bc)){
av_log(s, AV_LOG_ERROR, "Stream header %d checksum missmatch\n", stream_id);
return -1;
}
nut->stream[stream_id].rate_num= nom;
nut->stream[stream_id].rate_den= denom;
return 0;
}
static int decode_info_header(NUTContext *nut){
AVFormatContext *s= nut->avf;
ByteIOContext *bc = &s->pb;
get_packetheader(nut, bc, 8, 1);
for(;;){
int id= get_v(bc);
char *name, *type, custom_name[256], custom_type[256];
if(!id)
break;
else if(id >= sizeof(info_table)/sizeof(info_table[0])){
av_log(s, AV_LOG_ERROR, "info id is too large %d %d\n", id, sizeof(info_table)/sizeof(info_table[0]));
return -1;
}
type= info_table[id][1];
name= info_table[id][0];
//av_log(s, AV_LOG_DEBUG, "%d %s %s\n", id, type, name);
if(!type){
get_str(bc, custom_type, sizeof(custom_type));
type= custom_type;
}
if(!name){
get_str(bc, custom_name, sizeof(custom_name));
name= custom_name;
}
if(!strcmp(type, "v")){
int value= get_v(bc);
}else{
if(!strcmp(name, "Author"))
get_str(bc, s->author, sizeof(s->author));
else if(!strcmp(name, "Title"))
get_str(bc, s->title, sizeof(s->title));
else if(!strcmp(name, "Copyright"))
get_str(bc, s->copyright, sizeof(s->copyright));
else if(!strcmp(name, "Description"))
get_str(bc, s->comment, sizeof(s->comment));
else
get_str(bc, NULL, 0);
}
}
if(check_checksum(bc)){
av_log(s, AV_LOG_ERROR, "Info header checksum missmatch\n");
return -1;
}
return 0;
}
static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)
{
NUTContext *nut = s->priv_data;
ByteIOContext *bc = &s->pb;
int64_t pos;
int inited_stream_count;
nut->avf= s;
av_set_pts_info(s, 60, 1, AV_TIME_BASE);
/* main header */
pos=0;
for(;;){
if (find_startcode(bc, MAIN_STARTCODE, pos)<0){
av_log(s, AV_LOG_ERROR, "no main startcode found\n");
return -1;
}
pos= url_ftell(bc);
if(decode_main_header(nut) >= 0)
break;
}
s->bit_rate = 0;
nut->stream = av_malloc(sizeof(StreamContext)*nut->stream_count);
/* stream headers */
pos=0;
for(inited_stream_count=0; inited_stream_count < nut->stream_count;){
if (find_startcode(bc, STREAM_STARTCODE, pos)<0){
av_log(s, AV_LOG_ERROR, "not all stream headers found\n");
return -1;
}
pos= url_ftell(bc);
if(decode_stream_header(nut) >= 0)
inited_stream_count++;
}
/* info headers */
pos=0;
for(;;){
uint64_t startcode= find_any_startcode(bc, pos);
pos= url_ftell(bc);
if(startcode==0){
av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
return -1;
}else if(startcode == KEYFRAME_STARTCODE){
nut->next_startcode= startcode;
break;
}else if(startcode != INFO_STARTCODE){
continue;
}
decode_info_header(nut);
}
return 0;
}
static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code, int frame_type){
AVFormatContext *s= nut->avf;
StreamContext *stream;
ByteIOContext *bc = &s->pb;
int size, flags, size_mul, size_lsb, stream_id;
int key_frame = 0;
int64_t pts = 0;
const int prefix_len= frame_type == 2 ? 8+1 : 1;
const int64_t frame_start= url_ftell(bc) + prefix_len;
flags= nut->frame_code[frame_code].flags;
size_mul= nut->frame_code[frame_code].size_mul;
size_lsb= nut->frame_code[frame_code].size_lsb;
stream_id= nut->frame_code[frame_code].stream_id_plus1 - 1;
if(flags & FLAG_FRAME_TYPE){
reset(s);
if(get_packetheader(nut, bc, prefix_len, 0) < 0)
return -1;
if(frame_type!=2)
frame_type= 1;
}
if(stream_id==-1)
stream_id= get_v(bc);
if(stream_id >= s->nb_streams){
av_log(s, AV_LOG_ERROR, "illegal stream_id\n");
return -1;
}
stream= &nut->stream[stream_id];
// av_log(s, AV_LOG_DEBUG, "ft:%d ppts:%d %d %d\n", frame_type, stream->lru_pts_delta[0], stream->lru_pts_delta[1], stream->lru_pts_delta[2]);
if(flags & FLAG_PRED_KEY_FRAME){
if(flags & FLAG_KEY_FRAME)
key_frame= !stream->last_key_frame;
else
key_frame= stream->last_key_frame;
}else{
key_frame= !!(flags & FLAG_KEY_FRAME);
}
if(flags & FLAG_PTS){
if(flags & FLAG_FULL_PTS){
pts= get_v(bc);
}else{
int64_t mask = (1<<stream->msb_timestamp_shift)-1;
int64_t delta= stream->last_pts - mask/2;
pts= ((get_v(bc) - delta)&mask) + delta;
}
}else{
pts= stream->last_pts + stream->lru_pts_delta[(flags&12)>>2];
}
if(size_mul <= size_lsb){
size= stream->lru_size[size_lsb - size_mul];
}else{
if(flags & FLAG_DATA_SIZE)
size= size_mul*get_v(bc) + size_lsb;
else
size= size_lsb;
}
//av_log(s, AV_LOG_DEBUG, "fs:%lld fc:%d ft:%d kf:%d pts:%lld size:%d\n", frame_start, frame_code, frame_type, key_frame, pts, size);
if(url_ftell(bc) - nut->packet_start + size > nut->written_packet_size){
av_log(s, AV_LOG_ERROR, "frame size too large\n");
return -1;
}
av_new_packet(pkt, size);
get_buffer(bc, pkt->data, size);
pkt->stream_index = stream_id;
if (key_frame)
pkt->flags |= PKT_FLAG_KEY;
pkt->pts = pts * AV_TIME_BASE * stream->rate_den / stream->rate_num;
update(nut, stream_id, frame_start, frame_type, frame_code, key_frame, size, pts);
return 0;
}
static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
{
NUTContext *nut = s->priv_data;
ByteIOContext *bc = &s->pb;
int size, frame_code=0;
int frame_type= 0;
int64_t pos;
for(;;){
uint64_t tmp= nut->next_startcode;
nut->next_startcode=0;
if (url_feof(bc))
return -1;
if(!tmp){
frame_code = get_byte(bc);
if(frame_code == 'N'){
tmp= frame_code;
tmp<<=8 ; tmp |= get_byte(bc);
tmp<<=16; tmp |= get_be16(bc);
tmp<<=32; tmp |= get_be32(bc);
}
}
switch(tmp){
case KEYFRAME_STARTCODE:
frame_type = 2;
break;
case MAIN_STARTCODE:
case STREAM_STARTCODE:
case INDEX_STARTCODE:
get_packetheader(nut, bc, 8, 0);
url_fseek(bc, nut->written_packet_size + nut->packet_start, SEEK_SET);
break;
case INFO_STARTCODE:
if(decode_info_header(nut)<0)
goto resync;
break;
case 0:
if(decode_frame(nut, pkt, frame_code, frame_type)>=0)
return 0;
default:
resync:
frame_type = 0;
av_log(s, AV_LOG_DEBUG, "syncing from %lld\n", nut->packet_start+1);
tmp= find_any_startcode(bc, nut->packet_start+1);
if(tmp==0)
return -1;
av_log(s, AV_LOG_DEBUG, "sync\n");
if(url_is_streamed(bc)){
nut->next_startcode= tmp;
break;
}
pos= url_ftell(bc) - 8;
av_log(s, AV_LOG_DEBUG, "at %lld code=%llX\n", pos, tmp);
if(tmp==KEYFRAME_STARTCODE){
get_byte(bc);
}
get_v(bc);
size= get_v(bc);
while(size > 2 && size < 100000 && nut->packet_start < pos - size){
url_fseek(bc, pos - size, SEEK_SET);
frame_code= get_byte(bc);
if(!(nut->frame_code[ frame_code ].flags & FLAG_FRAME_TYPE))
break;
if(get_v(bc) != size)
break;
pos -= size;
size= get_v(bc);
av_log(s, AV_LOG_DEBUG, "steping back to %lld next %d\n", pos, size);
}
url_fseek(bc, pos, SEEK_SET);
nut->written_packet_size= size;
nut->packet_start= pos - size;
}
}
}
static int nut_read_close(AVFormatContext *s)
{
NUTContext *nut = s->priv_data;
int i;
for(i=0;i<s->nb_streams;i++) {
av_freep(&s->streams[i]->codec.extradata);
}
av_freep(&nut->stream);
return 0;
}
static AVInputFormat nut_iformat = {
"nut",
"nut format",
sizeof(NUTContext),
nut_probe,
nut_read_header,
nut_read_packet,
nut_read_close,
// nut_read_seek,
.extensions = "nut",
};
#ifdef CONFIG_ENCODERS
static AVOutputFormat nut_oformat = {
"nut",
"nut format",
"video/x-nut",
"nut",
sizeof(NUTContext),
#ifdef CONFIG_VORBIS
CODEC_ID_VORBIS,
#elif defined(CONFIG_MP3LAME)
CODEC_ID_MP3,
#else
CODEC_ID_MP2, /* AC3 needs liba52 decoder */
#endif
CODEC_ID_MPEG4,
nut_write_header,
nut_write_packet,
nut_write_trailer,
};
#endif //CONFIG_ENCODERS
int nut_init(void)
{
av_register_input_format(&nut_iformat);
#ifdef CONFIG_ENCODERS
av_register_output_format(&nut_oformat);
#endif //CONFIG_ENCODERS
return 0;
}