Update internal FFmpeg copy.

1 files changed, 775 insertions, 0 deletions

diff --git a/contrib/ffmpeg/libavformat/nutenc.c b/contrib/ffmpeg/libavformat/nutenc.c
new file mode 100644
index 000000000..5c0975c28
--- /dev/null
+++ b/contrib/ffmpeg/libavformat/nutenc.c
@@ -0,0 +1,775 @@
+/*
+ * nut muxer
+ * Copyright (c) 2004-2007 Michael Niedermayer
+ *
+ * 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
+ */
+
+#include "nut.h"
+#include "tree.h"
+#include "mpegaudiodata.h"
+
+static int find_expected_header(AVCodecContext *c, int size, int key_frame, uint8_t out[64]){
+    int sample_rate= c->sample_rate;
+
+    if(size>4096)
+        return 0;
+
+    AV_WB24(out, 1);
+
+    if(c->codec_id == CODEC_ID_MPEG4){
+        if(key_frame){
+            return 3;
+        }else{
+            out[3]= 0xB6;
+            return 4;
+        }
+    }else if(c->codec_id == CODEC_ID_MPEG1VIDEO || c->codec_id == CODEC_ID_MPEG2VIDEO){
+        return 3;
+    }else if(c->codec_id == CODEC_ID_H264){
+        return 3;
+    }else if(c->codec_id == CODEC_ID_MP3 || c->codec_id == CODEC_ID_MP2){
+        int lsf, mpeg25, sample_rate_index, bitrate_index, frame_size;
+        int layer= c->codec_id == CODEC_ID_MP3 ? 3 : 2;
+        unsigned int header= 0xFFF00000;
+
+        lsf     = sample_rate < (24000+32000)/2;
+        mpeg25  = sample_rate < (12000+16000)/2;
+        sample_rate <<= lsf + mpeg25;
+        if     (sample_rate < (32000 + 44100)/2) sample_rate_index=2;
+        else if(sample_rate < (44100 + 48000)/2) sample_rate_index=0;
+        else                                     sample_rate_index=1;
+
+        sample_rate= ff_mpa_freq_tab[sample_rate_index] >> (lsf + mpeg25);
+
+        for(bitrate_index=2; bitrate_index<30; bitrate_index++){
+            frame_size = ff_mpa_bitrate_tab[lsf][layer-1][bitrate_index>>1];
+            frame_size = (frame_size * 144000) / (sample_rate << lsf) + (bitrate_index&1);
+
+            if(frame_size == size)
+                break;
+        }
+
+        header |= (!lsf)<<19;
+        header |= (4-layer)<<17;
+        header |= 1<<16; //no crc
+        AV_WB32(out, header);
+        if(size <= 0)
+            return 2; //we guess theres no crc, if there is one the user clearly doesnt care about overhead
+        if(bitrate_index == 30)
+            return -1; //something is wrong ...
+
+        header |= (bitrate_index>>1)<<12;
+        header |= sample_rate_index<<10;
+        header |= (bitrate_index&1)<<9;
+
+        return 2; //FIXME actually put the needed ones in build_elision_headers()
+        return 3; //we guess that the private bit isnt set
+//FIXME the above asumtations should be checked, if these turn out false too often something should be done
+    }
+    return 0;
+}
+
+static int find_header_idx(AVFormatContext *s, AVCodecContext *c, int size, int frame_type){
+    NUTContext *nut = s->priv_data;
+    uint8_t out[64];
+    int i;
+    int len= find_expected_header(c, size, frame_type, out);
+
+//av_log(NULL, AV_LOG_ERROR, "expected_h len=%d size=%d codec_id=%d\n", len, size, c->codec_id);
+
+    for(i=1; i<nut->header_count; i++){
+        if(   len == nut->header_len[i]
+           && !memcmp(out, nut->header[i], len)){
+//    av_log(NULL, AV_LOG_ERROR, "found %d\n", i);
+            return i;
+        }
+    }
+//    av_log(NULL, AV_LOG_ERROR, "nothing found\n");
+    return 0;
+}
+
+static void build_elision_headers(AVFormatContext *s){
+    NUTContext *nut = s->priv_data;
+    int i;
+    //FIXME this is lame
+    //FIXME write a 2pass mode to find the maximal headers
+    const static uint8_t headers[][5]={
+        {3, 0x00, 0x00, 0x01},
+        {4, 0x00, 0x00, 0x01, 0xB6},
+        {2, 0xFF, 0xFA}, //mp3+crc
+        {2, 0xFF, 0xFB}, //mp3
+        {2, 0xFF, 0xFC}, //mp2+crc
+        {2, 0xFF, 0xFD}, //mp2
+    };
+
+    nut->header_count= 7;
+    for(i=1; i<nut->header_count; i++){
+        nut->header_len[i]=  headers[i-1][0];
+        nut->header    [i]= &headers[i-1][1];
+    }
+}
+
+static void build_frame_code(AVFormatContext *s){
+    NUTContext *nut = s->priv_data;
+    int key_frame, index, pred, stream_id;
+    int start=1;
+    int end= 254;
+    int keyframe_0_esc= s->nb_streams > 2;
+    int pred_table[10];
+    FrameCode *ft;
+
+    ft= &nut->frame_code[start];
+    ft->flags= FLAG_CODED;
+    ft->size_mul=1;
+    ft->pts_delta=1;
+    start++;
+
+    if(keyframe_0_esc){
+        /* keyframe = 0 escape */
+        FrameCode *ft= &nut->frame_code[start];
+        ft->flags= FLAG_STREAM_ID | FLAG_SIZE_MSB | FLAG_CODED_PTS;
+        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;
+
+            {
+                FrameCode *ft= &nut->frame_code[start2];
+                ft->flags= FLAG_KEY*key_frame;
+                ft->flags|= FLAG_SIZE_MSB | FLAG_CODED_PTS;
+                ft->stream_id= stream_id;
+                ft->size_mul=1;
+                if(is_audio)
+                    ft->header_idx= find_header_idx(s, codec, -1, key_frame);
+                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);
+            int pts;
+            for(pts=0; pts<2; pts++){
+                for(pred=0; pred<2; pred++){
+                    FrameCode *ft= &nut->frame_code[start2];
+                    ft->flags= FLAG_KEY*key_frame;
+                    ft->stream_id= stream_id;
+                    ft->size_mul=frame_bytes + 2;
+                    ft->size_lsb=frame_bytes + pred;
+                    ft->pts_delta=pts;
+                    ft->header_idx= find_header_idx(s, codec, frame_bytes + pred, key_frame);
+                    start2++;
+                }
+            }
+        }else{
+            FrameCode *ft= &nut->frame_code[start2];
+            ft->flags= FLAG_KEY | FLAG_SIZE_MSB;
+            ft->stream_id= stream_id;
+            ft->size_mul=1;
+            ft->pts_delta=1;
+            start2++;
+        }
+#endif
+
+        if(codec->has_b_frames){
+            pred_count=5;
+            pred_table[0]=-2;
+            pred_table[1]=-1;
+            pred_table[2]=1;
+            pred_table[3]=3;
+            pred_table[4]=4;
+        }else if(codec->codec_id == CODEC_ID_VORBIS){
+            pred_count=3;
+            pred_table[0]=2;
+            pred_table[1]=9;
+            pred_table[2]=16;
+        }else{
+            pred_count=1;
+            pred_table[0]=1;
+        }
+
+        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*key_frame;
+                ft->flags|= FLAG_SIZE_MSB;
+                ft->stream_id= stream_id;
+//FIXME use single byte size and pred from last
+                ft->size_mul= end3-start3;
+                ft->size_lsb= index - start3;
+                ft->pts_delta= pred_table[pred];
+                if(is_audio)
+                    ft->header_idx= find_header_idx(s, codec, -1, key_frame);
+            }
+        }
+    }
+    memmove(&nut->frame_code['N'+1], &nut->frame_code['N'], sizeof(FrameCode)*(255-'N'));
+    nut->frame_code[  0].flags=
+    nut->frame_code[255].flags=
+    nut->frame_code['N'].flags= FLAG_INVALID;
+}
+
+/**
+ * Gets the length in bytes which is needed to store val as v.
+ */
+static int get_length(uint64_t val){
+    int i=1;
+
+    while(val>>=7)
+        i++;
+
+    return i;
+}
+
+static void put_v(ByteIOContext *bc, uint64_t val){
+    int i= get_length(val);
+
+    while(--i>0)
+        put_byte(bc, 128 | (val>>(7*i)));
+
+    put_byte(bc, val&127);
+}
+
+static void put_t(NUTContext *nut, StreamContext *nus, ByteIOContext *bc, uint64_t val){
+    val *= nut->time_base_count;
+    val += nus->time_base - nut->time_base;
+    put_v(bc, val);
+}
+
+/**
+ * Stores a string as vb.
+ */
+static void put_str(ByteIOContext *bc, const char *string){
+    int len= strlen(string);
+
+    put_v(bc, len);
+    put_buffer(bc, string, len);
+}
+
+static void put_s(ByteIOContext *bc, int64_t val){
+    put_v(bc, 2*FFABS(val) - (val>0));
+}
+
+#ifdef TRACE
+static inline void put_v_trace(ByteIOContext *bc, uint64_t v, char *file, char *func, int line){
+    av_log(NULL, AV_LOG_DEBUG, "put_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
+
+    put_v(bc, v);
+}
+
+static inline void put_s_trace(ByteIOContext *bc, int64_t v, char *file, char *func, int line){
+    av_log(NULL, AV_LOG_DEBUG, "put_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
+
+    put_s(bc, v);
+}
+#define put_v(bc, v)  put_v_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
+#define put_s(bc, v)  put_s_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
+#endif
+
+//FIXME remove calculate_checksum
+static void put_packet(NUTContext *nut, ByteIOContext *bc, ByteIOContext *dyn_bc, int calculate_checksum, uint64_t startcode){
+    uint8_t *dyn_buf=NULL;
+    int dyn_size= url_close_dyn_buf(dyn_bc, &dyn_buf);
+    int forw_ptr= dyn_size + 4*calculate_checksum;
+
+    if(forw_ptr > 4096)
+        init_checksum(bc, ff_crc04C11DB7_update, 0);
+    put_be64(bc, startcode);
+    put_v(bc, forw_ptr);
+    if(forw_ptr > 4096)
+        put_le32(bc, get_checksum(bc));
+
+    if(calculate_checksum)
+        init_checksum(bc, ff_crc04C11DB7_update, 0);
+    put_buffer(bc, dyn_buf, dyn_size);
+    if(calculate_checksum)
+        put_le32(bc, get_checksum(bc));
+
+    av_free(dyn_buf);
+}
+
+static void write_mainheader(NUTContext *nut, ByteIOContext *bc){
+    int i, j, tmp_pts, tmp_flags, tmp_stream, tmp_mul, tmp_size, tmp_fields, tmp_head_idx;
+    int64_t tmp_match;
+
+    put_v(bc, 3); /* version */
+    put_v(bc, nut->avf->nb_streams);
+    put_v(bc, nut->max_distance);
+    put_v(bc, nut->time_base_count);
+
+    for(i=0; i<nut->time_base_count; i++){
+        put_v(bc, nut->time_base[i].num);
+        put_v(bc, nut->time_base[i].den);
+    }
+
+    tmp_pts=0;
+    tmp_mul=1;
+    tmp_stream=0;
+    tmp_match= 1-(1LL<<62);
+    tmp_head_idx= 0;
+    for(i=0; i<256;){
+        tmp_fields=0;
+        tmp_size=0;
+//        tmp_res=0;
+        if(tmp_pts    != nut->frame_code[i].pts_delta) tmp_fields=1;
+        if(tmp_mul    != nut->frame_code[i].size_mul ) tmp_fields=2;
+        if(tmp_stream != nut->frame_code[i].stream_id) tmp_fields=3;
+        if(tmp_size   != nut->frame_code[i].size_lsb ) tmp_fields=4;
+//        if(tmp_res    != nut->frame_code[i].res            ) tmp_fields=5;
+        if(tmp_head_idx!=nut->frame_code[i].header_idx)tmp_fields=8;
+
+        tmp_pts   = nut->frame_code[i].pts_delta;
+        tmp_flags = nut->frame_code[i].flags;
+        tmp_stream= nut->frame_code[i].stream_id;
+        tmp_mul   = nut->frame_code[i].size_mul;
+        tmp_size  = nut->frame_code[i].size_lsb;
+//        tmp_res   = nut->frame_code[i].res;
+        tmp_head_idx= nut->frame_code[i].header_idx;
+
+        for(j=0; i<256; j++,i++){
+            if(i == 'N'){
+                j--;
+                continue;
+            }
+            if(nut->frame_code[i].pts_delta != tmp_pts   ) break;
+            if(nut->frame_code[i].flags     != tmp_flags ) break;
+            if(nut->frame_code[i].stream_id != tmp_stream) break;
+            if(nut->frame_code[i].size_mul  != tmp_mul   ) break;
+            if(nut->frame_code[i].size_lsb  != tmp_size+j) break;
+//            if(nut->frame_code[i].res       != tmp_res   ) break;
+            if(nut->frame_code[i].header_idx!= tmp_head_idx) break;
+        }
+        if(j != tmp_mul - tmp_size) tmp_fields=6;
+
+        put_v(bc, tmp_flags);
+        put_v(bc, tmp_fields);
+        if(tmp_fields>0) put_s(bc, tmp_pts);
+        if(tmp_fields>1) put_v(bc, tmp_mul);
+        if(tmp_fields>2) put_v(bc, tmp_stream);
+        if(tmp_fields>3) put_v(bc, tmp_size);
+        if(tmp_fields>4) put_v(bc, 0 /*tmp_res*/);
+        if(tmp_fields>5) put_v(bc, j);
+        if(tmp_fields>6) put_v(bc, tmp_match);
+        if(tmp_fields>7) put_v(bc, tmp_head_idx);
+    }
+    put_v(bc, nut->header_count-1);
+    for(i=1; i<nut->header_count; i++){
+        put_v(bc, nut->header_len[i]);
+        put_buffer(bc, nut->header[i], nut->header_len[i]);
+    }
+}
+
+static int write_streamheader(NUTContext *nut, ByteIOContext *bc, AVCodecContext *codec, int i){
+    put_v(bc, i);
+    switch(codec->codec_type){
+    case CODEC_TYPE_VIDEO: put_v(bc, 0); break;
+    case CODEC_TYPE_AUDIO: put_v(bc, 1); break;
+//    case CODEC_TYPE_TEXT : put_v(bc, 2); break;
+    default              : put_v(bc, 3); break;
+    }
+    put_v(bc, 4);
+    if (codec->codec_tag){
+        put_le32(bc, codec->codec_tag);
+    }else
+        return -1;
+
+    put_v(bc, nut->stream[i].time_base - nut->time_base);
+    put_v(bc, nut->stream[i].msb_pts_shift);
+    put_v(bc, nut->stream[i].max_pts_distance);
+    put_v(bc, codec->has_b_frames);
+    put_byte(bc, 0); /* flags: 0x1 - fixed_fps, 0x2 - index_present */
+
+    put_v(bc, codec->extradata_size);
+    put_buffer(bc, codec->extradata, codec->extradata_size);
+
+    switch(codec->codec_type){
+    case CODEC_TYPE_AUDIO:
+        put_v(bc, codec->sample_rate);
+        put_v(bc, 1);
+        put_v(bc, codec->channels);
+        break;
+    case CODEC_TYPE_VIDEO:
+        put_v(bc, codec->width);
+        put_v(bc, codec->height);
+
+        if(codec->sample_aspect_ratio.num<=0 || codec->sample_aspect_ratio.den<=0){
+            put_v(bc, 0);
+            put_v(bc, 0);
+        }else{
+            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;
+    }
+    return 0;
+}
+
+static int add_info(ByteIOContext *bc, const char *type, const char *value){
+    put_str(bc, type);
+    put_s(bc, -1);
+    put_str(bc, value);
+    return 1;
+}
+
+static int write_globalinfo(NUTContext *nut, ByteIOContext *bc){
+    AVFormatContext *s= nut->avf;
+    ByteIOContext *dyn_bc;
+    uint8_t *dyn_buf=NULL;
+    int count=0, dyn_size;
+    int ret = url_open_dyn_buf(&dyn_bc);
+    if(ret < 0)
+        return ret;
+
+    if(s->title    [0]) count+= add_info(dyn_bc, "Title"    , s->title);
+    if(s->author   [0]) count+= add_info(dyn_bc, "Author"   , s->author);
+    if(s->copyright[0]) count+= add_info(dyn_bc, "Copyright", s->copyright);
+    if(!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT))
+                        count+= add_info(dyn_bc, "Encoder"  , LIBAVFORMAT_IDENT);
+
+    put_v(bc, 0); //stream_if_plus1
+    put_v(bc, 0); //chapter_id
+    put_v(bc, 0); //timestamp_start
+    put_v(bc, 0); //length
+
+    put_v(bc, count);
+
+    dyn_size= url_close_dyn_buf(dyn_bc, &dyn_buf);
+    put_buffer(bc, dyn_buf, dyn_size);
+    av_free(dyn_buf);
+    return 0;
+}
+
+static int write_headers(NUTContext *nut, ByteIOContext *bc){
+    ByteIOContext *dyn_bc;
+    int i, ret;
+
+    ret = url_open_dyn_buf(&dyn_bc);
+    if(ret < 0)
+        return ret;
+    write_mainheader(nut, dyn_bc);
+    put_packet(nut, bc, dyn_bc, 1, MAIN_STARTCODE);
+
+    for (i=0; i < nut->avf->nb_streams; i++){
+        AVCodecContext *codec = nut->avf->streams[i]->codec;
+
+        ret = url_open_dyn_buf(&dyn_bc);
+        if(ret < 0)
+            return ret;
+        write_streamheader(nut, dyn_bc, codec, i);
+        put_packet(nut, bc, dyn_bc, 1, STREAM_STARTCODE);
+    }
+
+    ret = url_open_dyn_buf(&dyn_bc);
+    if(ret < 0)
+        return ret;
+    write_globalinfo(nut, dyn_bc);
+    put_packet(nut, bc, dyn_bc, 1, INFO_STARTCODE);
+
+    nut->last_syncpoint_pos= INT_MIN;
+    nut->header_count++;
+    return 0;
+}
+
+static int write_header(AVFormatContext *s){
+    NUTContext *nut = s->priv_data;
+    ByteIOContext *bc = s->pb;
+    int i, j;
+
+    nut->avf= s;
+
+    nut->stream   = av_mallocz(sizeof(StreamContext)*s->nb_streams);
+    nut->time_base= av_mallocz(sizeof(AVRational   )*s->nb_streams);
+
+    for(i=0; i<s->nb_streams; i++){
+        AVStream *st= s->streams[i];
+        int ssize;
+        AVRational time_base;
+        ff_parse_specific_params(st->codec, &time_base.den, &ssize, &time_base.num);
+
+        av_set_pts_info(st, 64, time_base.num, time_base.den);
+
+        for(j=0; j<nut->time_base_count; j++){
+            if(!memcmp(&time_base, &nut->time_base[j], sizeof(AVRational))){
+                break;
+            }
+        }
+        nut->time_base[j]= time_base;
+        nut->stream[i].time_base= &nut->time_base[j];
+        if(j==nut->time_base_count)
+            nut->time_base_count++;
+
+        if(av_q2d(time_base) >= 0.001)
+            nut->stream[i].msb_pts_shift = 7;
+        else
+            nut->stream[i].msb_pts_shift = 14;
+        nut->stream[i].max_pts_distance= FFMAX(1/av_q2d(time_base), 1);
+    }
+
+    nut->max_distance = MAX_DISTANCE;
+    build_elision_headers(s);
+    build_frame_code(s);
+    assert(nut->frame_code['N'].flags == FLAG_INVALID);
+
+    put_buffer(bc, ID_STRING, strlen(ID_STRING));
+    put_byte(bc, 0);
+
+    write_headers(nut, bc);
+
+    put_flush_packet(bc);
+
+    //FIXME index
+
+    return 0;
+}
+
+static int get_needed_flags(NUTContext *nut, StreamContext *nus, FrameCode *fc, AVPacket *pkt){
+    int flags= 0;
+
+    if(pkt->flags & PKT_FLAG_KEY                ) flags |= FLAG_KEY;
+    if(pkt->stream_index != fc->stream_id       ) flags |= FLAG_STREAM_ID;
+    if(pkt->size / fc->size_mul                 ) flags |= FLAG_SIZE_MSB;
+    if(pkt->pts - nus->last_pts != fc->pts_delta) flags |= FLAG_CODED_PTS;
+    if(pkt->size > 2*nut->max_distance          ) flags |= FLAG_CHECKSUM;
+    if(FFABS(pkt->pts - nus->last_pts)
+                         > nus->max_pts_distance) flags |= FLAG_CHECKSUM;
+    if(   pkt->size < nut->header_len[fc->header_idx]
+       || (pkt->size > 4096 && fc->header_idx)
+       || memcmp(pkt->data, nut->header[fc->header_idx], nut->header_len[fc->header_idx]))
+                                                  flags |= FLAG_HEADER_IDX;
+
+    return flags | (fc->flags & FLAG_CODED);
+}
+
+static int find_best_header_idx(NUTContext *nut, AVPacket *pkt){
+    int i;
+    int best_i  = 0;
+    int best_len= 0;
+
+    if(pkt->size > 4096)
+        return 0;
+
+    for(i=1; i<nut->header_count; i++){
+        if(   pkt->size >= nut->header_len[i]
+           &&  nut->header_len[i] > best_len
+           && !memcmp(pkt->data, nut->header[i], nut->header_len[i])){
+            best_i= i;
+            best_len= nut->header_len[i];
+        }
+    }
+    return best_i;
+}
+
+static int write_packet(AVFormatContext *s, AVPacket *pkt){
+    NUTContext *nut = s->priv_data;
+    StreamContext *nus= &nut->stream[pkt->stream_index];
+    ByteIOContext *bc = s->pb, *dyn_bc;
+    FrameCode *fc;
+    int64_t coded_pts;
+    int best_length, frame_code, flags, needed_flags, i, header_idx, best_header_idx;
+    int key_frame = !!(pkt->flags & PKT_FLAG_KEY);
+    int store_sp=0;
+    int ret;
+
+    if(1LL<<(20+3*nut->header_count) <= url_ftell(bc))
+        write_headers(nut, bc);
+
+    if(key_frame && !(nus->last_flags & FLAG_KEY))
+        store_sp= 1;
+
+    if(pkt->size + 30/*FIXME check*/ + url_ftell(bc) >= nut->last_syncpoint_pos + nut->max_distance)
+        store_sp= 1;
+
+//FIXME: Ensure store_sp is 1 in the first place.
+
+    if(store_sp){
+        syncpoint_t *sp, dummy= {.pos= INT64_MAX};
+
+        ff_nut_reset_ts(nut, *nus->time_base, pkt->dts);
+        for(i=0; i<s->nb_streams; i++){
+            AVStream *st= s->streams[i];
+            int64_t dts_tb = av_rescale_rnd(pkt->dts,
+                nus->time_base->num * (int64_t)nut->stream[i].time_base->den,
+                nus->time_base->den * (int64_t)nut->stream[i].time_base->num,
+                AV_ROUND_DOWN);
+            int index= av_index_search_timestamp(st, dts_tb, AVSEEK_FLAG_BACKWARD);
+            if(index>=0) dummy.pos= FFMIN(dummy.pos, st->index_entries[index].pos);
+        }
+        if(dummy.pos == INT64_MAX)
+            dummy.pos= 0;
+        sp= av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, NULL);
+
+        nut->last_syncpoint_pos= url_ftell(bc);
+        ret = url_open_dyn_buf(&dyn_bc);
+        if(ret < 0)
+            return ret;
+        put_t(nut, nus, dyn_bc, pkt->dts);
+        put_v(dyn_bc, sp ? (nut->last_syncpoint_pos - sp->pos)>>4 : 0);
+        put_packet(nut, bc, dyn_bc, 1, SYNCPOINT_STARTCODE);
+
+        ff_nut_add_sp(nut, nut->last_syncpoint_pos, 0/*unused*/, pkt->dts);
+    }
+    assert(nus->last_pts != AV_NOPTS_VALUE);
+
+    coded_pts = pkt->pts & ((1<<nus->msb_pts_shift)-1);
+    if(ff_lsb2full(nus, coded_pts) != pkt->pts)
+        coded_pts= pkt->pts + (1<<nus->msb_pts_shift);
+
+    best_header_idx= find_best_header_idx(nut, pkt);
+
+    best_length=INT_MAX;
+    frame_code= -1;
+    for(i=0; i<256; i++){
+        int length= 0;
+        FrameCode *fc= &nut->frame_code[i];
+        int flags= fc->flags;
+
+        if(flags & FLAG_INVALID)
+            continue;
+        needed_flags= get_needed_flags(nut, nus, fc, pkt);
+
+        if(flags & FLAG_CODED){
+            length++;
+            flags = needed_flags;
+        }
+
+        if((flags & needed_flags) != needed_flags)
+            continue;
+
+        if((flags ^ needed_flags) & FLAG_KEY)
+            continue;
+
+        if(flags & FLAG_STREAM_ID)
+            length+= get_length(pkt->stream_index);
+
+        if(pkt->size % fc->size_mul != fc->size_lsb)
+            continue;
+        if(flags & FLAG_SIZE_MSB)
+            length += get_length(pkt->size / fc->size_mul);
+
+        if(flags & FLAG_CHECKSUM)
+            length+=4;
+
+        if(flags & FLAG_CODED_PTS)
+            length += get_length(coded_pts);
+
+        if(   (flags & FLAG_CODED)
+           && nut->header_len[best_header_idx] > nut->header_len[fc->header_idx]+1){
+            flags |= FLAG_HEADER_IDX;
+        }
+
+        if(flags & FLAG_HEADER_IDX){
+            length += 1 - nut->header_len[best_header_idx];
+        }else{
+            length -= nut->header_len[fc->header_idx];
+        }
+
+        length*=4;
+        length+= !(flags & FLAG_CODED_PTS);
+        length+= !(flags & FLAG_CHECKSUM);
+
+        if(length < best_length){
+            best_length= length;
+            frame_code=i;
+        }
+    }
+    assert(frame_code != -1);
+    fc= &nut->frame_code[frame_code];
+    flags= fc->flags;
+    needed_flags= get_needed_flags(nut, nus, fc, pkt);
+    header_idx= fc->header_idx;
+
+    init_checksum(bc, ff_crc04C11DB7_update, 0);
+    put_byte(bc, frame_code);
+    if(flags & FLAG_CODED){
+        put_v(bc, (flags^needed_flags) & ~(FLAG_CODED));
+        flags = needed_flags;
+    }
+    if(flags & FLAG_STREAM_ID)  put_v(bc, pkt->stream_index);
+    if(flags & FLAG_CODED_PTS)  put_v(bc, coded_pts);
+    if(flags & FLAG_SIZE_MSB)   put_v(bc, pkt->size / fc->size_mul);
+    if(flags & FLAG_HEADER_IDX) put_v(bc, header_idx= best_header_idx);
+
+    if(flags & FLAG_CHECKSUM)   put_le32(bc, get_checksum(bc));
+    else                        get_checksum(bc);
+
+    put_buffer(bc, pkt->data + nut->header_len[header_idx], pkt->size - nut->header_len[header_idx]);
+    nus->last_flags= flags;
+    nus->last_pts= pkt->pts;
+
+    //FIXME just store one per syncpoint
+    if(flags & FLAG_KEY)
+        av_add_index_entry(
+            s->streams[pkt->stream_index],
+            nut->last_syncpoint_pos,
+            pkt->pts,
+            0,
+            0,
+            AVINDEX_KEYFRAME);
+
+    return 0;
+}
+
+static int write_trailer(AVFormatContext *s){
+    NUTContext *nut= s->priv_data;
+    ByteIOContext *bc= s->pb;
+
+    while(nut->header_count<3)
+        write_headers(nut, bc);
+    put_flush_packet(bc);
+
+    return 0;
+}
+
+AVOutputFormat nut_muxer = {
+    "nut",
+    "nut format",
+    "video/x-nut",
+    "nut",
+    sizeof(NUTContext),
+#ifdef CONFIG_LIBVORBIS
+    CODEC_ID_VORBIS,
+#elif defined(CONFIG_LIBMP3LAME)
+    CODEC_ID_MP3,
+#else
+    CODEC_ID_MP2, /* AC3 needs liba52 decoder */
+#endif
+    CODEC_ID_MPEG4,
+    write_header,
+    write_packet,
+    write_trailer,
+    .flags = AVFMT_GLOBALHEADER,
+    .codec_tag= (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, 0},
+};