Как объединить сплит FLV файлы?

Not a complete answer yet but FLVMeta and a partial reading of Adobe's spec are beginning to shine light on things. From an FLVMeta full dump the tags or sections of data look like this:

 --- Tag #1019 at 0xCBEB5 (835253) --- Tag type: audio Body length: 213 Timestamp: 124957 * Sound type: stereo * Sound size: 16 * Sound rate: 44 * Sound format: AAC Previous tag size: 224 --- Tag #1020 at 0xCBF99 (835481) --- Tag type: video Body length: 1201 Timestamp: 124960 * Video codec: AVC * Video frame type: inter frame Previous tag size: 1212 --- Tag #1021 at 0xCC459 (836697) --- Tag type: audio Body length: 225 Timestamp: 124980 * Sound type: stereo * Sound size: 16 * Sound rate: 44 * Sound format: AAC Previous tag size: 236 --- Tag #1022 at 0xCC549 (836937) --- Tag type: video Body length: 542 Timestamp: 125000 * Video codec: AVC * Video frame type: inter frame Previous tag size: 553 

So you could read the header into one file, put all the tags into 1 file each, then reconstruct however many input files into however many output files you wanted. Each "tag" I'd call a block, but it's a chunk of data. You don't have to manipulate them in real time. Each has a timestamp, you just have to put them together in that order and don't split a tag across files.

I wish FLVMeta had more useful output for moving things around under program control like tab or comma-delimited data. Maybe even create an SQLite database for each project, put all the audio tags in one table, video in another, script in another. Maybe I'll do that yet since it's open source and on Github. It'd be simpler if flvs weren't big-endian and I'm on a little-endian machine. All integers are big-endian, like on a Mac.

Done finally. I ended up using a C program I wrote to concatenate them once I solved the bug that EOF on the first input file ended up as an FF or -1 in the output file, which stopped players and converters at that point.

flvmeta still gave warnings on the output of this but I was able to convert it to an mp4 using:

 ffmpeg -i out4.flv -vcodec copy -acodec copy out4.mp4 /* My flv concat, a single-use program */ #include <stdio.h> // don't need most of these headers #include <stdlib.h> #include <string.h> #include <endian.h> // FLVs have big endian values #include <unistd.h> #include <fcntl.h> #include <inttypes.h> FILE *opf; void docopy(char *fn, uint ofs) { FILE *ipf; unsigned char ch; ipf = fopen(fn,"r"); if (ipf == NULL) { printf("Failed to open %s\n",fn); fclose(opf); exit(1); } fseek(ipf,ofs,SEEK_SET); // jump to passed in offset while (!feof(ipf)) { // not super efficient ch = fgetc(ipf); // this DOES have an effect, it stops the -1 from being written if (!feof(ipf)) fputc(ch,opf); } printf("outfile now at %x\n",(unsigned int) ftell(opf)); fclose(ipf); } void outhdr(void) { // write boilerplate flv header opf = fopen("out4.flv","w"); if (opf == NULL) { printf("Error creating new output file.\n"); exit(1); } fprintf(opf,"FLV%c%c%c%c%c%c",1,5,0,0,0,9); // audio and video enabled // This becomes the first PreviousTagSize: fprintf(opf,"%c%c%c%c",0,0,0,0); // flvmeta seems to approve } int main(void) { outhdr(); // write a vanilla header docopy("media1.flv", 13); // copy, starting at byte 13 docopy("media2.flv", 13); docopy("media3.flv", 13); fclose(opf); return 0; }