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ffmpeg / libavformat / nutenc.c @ 0809b51e

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/*
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 * nut muxer
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 * Copyright (c) 2004-2007 Michael Niedermayer
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#include "nut.h"
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#define TRACE
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static void build_frame_code(AVFormatContext *s){
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    NUTContext *nut = s->priv_data;
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    int key_frame, index, pred, stream_id;
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    int start=1;
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    int end= 254;
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    int keyframe_0_esc= s->nb_streams > 2;
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    int pred_table[10];
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    if(keyframe_0_esc){
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        /* keyframe = 0 escape */
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        FrameCode *ft= &nut->frame_code[start];
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        ft->flags= FLAG_STREAM_ID | FLAG_SIZE_MSB | FLAG_CODED_PTS;
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        ft->size_mul=1;
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        start++;
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    }
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    for(stream_id= 0; stream_id<s->nb_streams; stream_id++){
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        int start2= start + (end-start)*stream_id / s->nb_streams;
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        int end2  = start + (end-start)*(stream_id+1) / s->nb_streams;
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        AVCodecContext *codec = s->streams[stream_id]->codec;
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        int is_audio= codec->codec_type == CODEC_TYPE_AUDIO;
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        int intra_only= /*codec->intra_only || */is_audio;
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        int pred_count;
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        for(key_frame=0; key_frame<2; key_frame++){
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            if(intra_only && keyframe_0_esc && key_frame==0)
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                continue;
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            {
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                FrameCode *ft= &nut->frame_code[start2];
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                ft->flags= FLAG_KEY*key_frame;
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                ft->flags|= FLAG_SIZE_MSB | FLAG_CODED_PTS;
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                ft->stream_id= stream_id;
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                ft->size_mul=1;
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                start2++;
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            }
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        }
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        key_frame= intra_only;
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#if 1
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        if(is_audio){
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            int frame_bytes= codec->frame_size*(int64_t)codec->bit_rate / (8*codec->sample_rate);
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            int pts;
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            for(pts=0; pts<2; pts++){
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                for(pred=0; pred<2; pred++){
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                    FrameCode *ft= &nut->frame_code[start2];
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                    ft->flags= FLAG_KEY*key_frame;
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                    ft->stream_id= stream_id;
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                    ft->size_mul=frame_bytes + 2;
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                    ft->size_lsb=frame_bytes + pred;
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                    ft->pts_delta=pts;
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                    start2++;
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                }
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            }
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        }else{
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            FrameCode *ft= &nut->frame_code[start2];
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            ft->flags= FLAG_KEY | FLAG_SIZE_MSB;
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            ft->stream_id= stream_id;
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            ft->size_mul=1;
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            ft->pts_delta=1;
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            start2++;
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        }
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#endif
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        if(codec->has_b_frames){
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            pred_count=5;
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            pred_table[0]=-2;
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            pred_table[1]=-1;
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            pred_table[2]=1;
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            pred_table[3]=3;
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            pred_table[4]=4;
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        }else if(codec->codec_id == CODEC_ID_VORBIS){
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            pred_count=3;
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            pred_table[0]=2;
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            pred_table[1]=9;
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            pred_table[2]=16;
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        }else{
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            pred_count=1;
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            pred_table[0]=1;
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        }
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        for(pred=0; pred<pred_count; pred++){
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            int start3= start2 + (end2-start2)*pred / pred_count;
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            int end3  = start2 + (end2-start2)*(pred+1) / pred_count;
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            for(index=start3; index<end3; index++){
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                FrameCode *ft= &nut->frame_code[index];
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                ft->flags= FLAG_KEY*key_frame;
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                ft->flags|= FLAG_SIZE_MSB;
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                ft->stream_id= stream_id;
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//FIXME use single byte size and pred from last
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                ft->size_mul= end3-start3;
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                ft->size_lsb= index - start3;
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                ft->pts_delta= pred_table[pred];
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            }
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        }
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    }
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    memmove(&nut->frame_code['N'+1], &nut->frame_code['N'], sizeof(FrameCode)*(255-'N'));
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    nut->frame_code[  0].flags=
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    nut->frame_code[255].flags=
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    nut->frame_code['N'].flags= FLAG_INVALID;
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}
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/**
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 * Gets the length in bytes which is needed to store val as v.
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 */
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static int get_length(uint64_t val){
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    int i=1;
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    while(val>>=7)
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        i++;
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    return i;
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}
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static void put_v(ByteIOContext *bc, uint64_t val){
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    int i= get_length(val);
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    while(--i>0)
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        put_byte(bc, 128 | (val>>(7*i)));
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    put_byte(bc, val&127);
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}
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/**
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 * stores a string as vb.
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 */
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static void put_str(ByteIOContext *bc, const char *string){
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    int len= strlen(string);
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    put_v(bc, len);
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    put_buffer(bc, string, len);
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}
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static void put_s(ByteIOContext *bc, int64_t val){
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    put_v(bc, 2*FFABS(val) - (val>0));
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}
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#ifdef TRACE
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static inline void put_v_trace(ByteIOContext *bc, uint64_t v, char *file, char *func, int line){
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    printf("get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
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    put_v(bc, v);
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}
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static inline void put_s_trace(ByteIOContext *bc, int64_t v, char *file, char *func, int line){
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    printf("get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
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    put_s(bc, v);
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}
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#define put_v(bc, v)  put_v_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
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#define put_s(bc, v)  put_s_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
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#endif
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static int put_packetheader(NUTContext *nut, ByteIOContext *bc, int max_size, int calculate_checksum){
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    put_flush_packet(bc);
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    nut->packet_start= url_ftell(bc) - 8;
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    nut->written_packet_size = max_size;
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    /* packet header */
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    put_v(bc, nut->written_packet_size); /* forward ptr */
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    if(calculate_checksum)
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        init_checksum(bc, av_crc04C11DB7_update, 0);
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    return 0;
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}
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/**
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 *
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 * must not be called more then once per packet
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 */
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static int update_packetheader(NUTContext *nut, ByteIOContext *bc, int additional_size, int calculate_checksum){
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    int64_t start= nut->packet_start;
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    int64_t cur= url_ftell(bc);
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    int size= cur - start - get_length(nut->written_packet_size) - 8;
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    if(calculate_checksum)
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        size += 4;
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    if(size != nut->written_packet_size){
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        int i;
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        assert( size <= nut->written_packet_size );
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        url_fseek(bc, start + 8, SEEK_SET);
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        for(i=get_length(size); i < get_length(nut->written_packet_size); i++)
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            put_byte(bc, 128);
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        put_v(bc, size);
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        url_fseek(bc, cur, SEEK_SET);
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        nut->written_packet_size= size; //FIXME may fail if multiple updates with differing sizes, as get_length may differ
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        if(calculate_checksum)
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            put_le32(bc, get_checksum(bc));
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    }
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    return 0;
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}
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static void write_mainheader(NUTContext *nut, ByteIOContext *bc){
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    int i, j, tmp_pts, tmp_flags, tmp_stream, tmp_mul, tmp_size, tmp_fields;
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    put_v(bc, 2); /* version */
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    put_v(bc, nut->avf->nb_streams);
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    put_v(bc, MAX_DISTANCE);
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    put_v(bc, nut->time_base_count);
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    for(i=0; i<nut->time_base_count; i++){
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        put_v(bc, nut->time_base[i].num);
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        put_v(bc, nut->time_base[i].den);
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    }
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    tmp_pts=0;
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    tmp_mul=1;
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    tmp_stream=0;
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    for(i=0; i<256;){
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        tmp_fields=0;
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        tmp_size=0;
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//        tmp_res=0;
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        if(tmp_pts    != nut->frame_code[i].pts_delta) tmp_fields=1;
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        if(tmp_mul    != nut->frame_code[i].size_mul ) tmp_fields=2;
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        if(tmp_stream != nut->frame_code[i].stream_id) tmp_fields=3;
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        if(tmp_size   != nut->frame_code[i].size_lsb ) tmp_fields=4;
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//        if(tmp_res    != nut->frame_code[i].res            ) tmp_fields=5;
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        tmp_pts   = nut->frame_code[i].pts_delta;
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        tmp_flags = nut->frame_code[i].flags;
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        tmp_stream= nut->frame_code[i].stream_id;
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        tmp_mul   = nut->frame_code[i].size_mul;
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        tmp_size  = nut->frame_code[i].size_lsb;
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//        tmp_res   = nut->frame_code[i].res;
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        for(j=0; i<256; j++,i++){
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            if(i == 'N'){
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                j--;
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                continue;
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            }
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            if(nut->frame_code[i].pts_delta != tmp_pts   ) break;
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            if(nut->frame_code[i].flags     != tmp_flags ) break;
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            if(nut->frame_code[i].stream_id != tmp_stream) break;
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            if(nut->frame_code[i].size_mul  != tmp_mul   ) break;
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            if(nut->frame_code[i].size_lsb  != tmp_size+j) break;
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//            if(nut->frame_code[i].res       != tmp_res   ) break;
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        }
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        if(j != tmp_mul - tmp_size) tmp_fields=6;
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        put_v(bc, tmp_flags);
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        put_v(bc, tmp_fields);
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        if(tmp_fields>0) put_s(bc, tmp_pts);
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        if(tmp_fields>1) put_v(bc, tmp_mul);
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        if(tmp_fields>2) put_v(bc, tmp_stream);
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        if(tmp_fields>3) put_v(bc, tmp_size);
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        if(tmp_fields>4) put_v(bc, 0 /*tmp_res*/);
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        if(tmp_fields>5) put_v(bc, j);
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    }
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}
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static int write_streamheader(NUTContext *nut, ByteIOContext *bc, AVCodecContext *codec, int i){
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    put_v(bc, i);
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    switch(codec->codec_type){
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    case CODEC_TYPE_VIDEO: put_v(bc, 0); break;
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    case CODEC_TYPE_AUDIO: put_v(bc, 1); break;
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//    case CODEC_TYPE_TEXT : put_v(bc, 2); break;
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    default              : put_v(bc, 3); break;
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    }
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    put_v(bc, 4);
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    if (codec->codec_tag){
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        put_le32(bc, codec->codec_tag);
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    }else
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        return -1;
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    put_v(bc, (nut->stream[i].time_base - nut->time_base)/sizeof(AVRational));
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    put_v(bc, nut->stream[i].msb_pts_shift);
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    put_v(bc, nut->stream[i].max_pts_distance);
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    put_v(bc, codec->has_b_frames);
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    put_byte(bc, 0); /* flags: 0x1 - fixed_fps, 0x2 - index_present */
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    put_v(bc, codec->extradata_size);
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    put_buffer(bc, codec->extradata, codec->extradata_size);
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    switch(codec->codec_type){
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    case CODEC_TYPE_AUDIO:
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        put_v(bc, codec->sample_rate);
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        put_v(bc, 1);
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        put_v(bc, codec->channels);
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        break;
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    case CODEC_TYPE_VIDEO:
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        put_v(bc, codec->width);
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        put_v(bc, codec->height);
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        put_v(bc, codec->sample_aspect_ratio.num);
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        put_v(bc, codec->sample_aspect_ratio.den);
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        put_v(bc, 0); /* csp type -- unknown */
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        break;
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    default:
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        break;
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    }
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    return 0;
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}
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static int write_header(AVFormatContext *s){
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    NUTContext *nut = s->priv_data;
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    ByteIOContext *bc = &s->pb;
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    AVCodecContext *codec;
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    int i, j;
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    nut->avf= s;
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    nut->stream   = av_mallocz(sizeof(StreamContext)*s->nb_streams);
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    nut->time_base= av_mallocz(sizeof(AVRational   )*s->nb_streams);
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    for(i=0; i<s->nb_streams; i++){
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        AVStream *st= s->streams[i];
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        int ssize;
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        AVRational time_base;
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        ff_parse_specific_params(st->codec, &time_base.den, &ssize, &time_base.num);
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        av_set_pts_info(st, 64, time_base.num, time_base.den);
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        for(j=0; j<nut->time_base_count; j++){
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            if(!memcmp(&time_base, &nut->time_base[j], sizeof(AVRational))){
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                break;
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            }
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        }
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        nut->time_base[j]= time_base;
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        nut->stream[i].time_base= &nut->time_base[j];
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        if(j==nut->time_base_count)
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            nut->time_base_count++;
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        if(av_q2d(time_base) >= 0.001)
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            nut->stream[i].msb_pts_shift = 7;
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        else
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            nut->stream[i].msb_pts_shift = 14;
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        nut->stream[i].max_pts_distance= FFMAX(1/av_q2d(time_base), 1);
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    }
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362
    build_frame_code(s);
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    assert(nut->frame_code['N'].flags == FLAG_INVALID);
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    put_buffer(bc, ID_STRING, strlen(ID_STRING));
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    put_byte(bc, 0);
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    /* main header */
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    put_be64(bc, MAIN_STARTCODE);
370
    put_packetheader(nut, bc, 120+5*256/*FIXME check*/, 1);
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    write_mainheader(nut, bc);
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    update_packetheader(nut, bc, 0, 1);
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    for (i=0; i < s->nb_streams; i++){
375
        codec = s->streams[i]->codec;
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        put_be64(bc, STREAM_STARTCODE);
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        put_packetheader(nut, bc, 120/*FIXME check*/ + codec->extradata_size, 1);
379
        write_streamheader(nut, bc, codec, i);
380
        update_packetheader(nut, bc, 0, 1);
381
    }
382

    
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    put_flush_packet(bc);
384

    
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    //FIXME info header, header repeation, header packet CRC, ...
386

    
387
    return 0;
388
}
389

    
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static int write_packet(AVFormatContext *s, AVPacket *pkt){
391
    //FIXME
392
    return 0;
393
}
394

    
395
AVOutputFormat nut_muxer = {
396
    "nut",
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    "nut format",
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    "video/x-nut",
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    "nut",
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    sizeof(NUTContext),
401
#ifdef CONFIG_LIBVORBIS
402
    CODEC_ID_VORBIS,
403
#elif defined(CONFIG_LIBMP3LAME)
404
    CODEC_ID_MP3,
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#else
406
    CODEC_ID_MP2, /* AC3 needs liba52 decoder */
407
#endif
408
    CODEC_ID_MPEG4,
409
    write_header,
410
    write_packet,
411
//    write_trailer,
412
    .flags = AVFMT_GLOBALHEADER,
413
    .codec_tag= (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, 0},
414
};