--- /dev/null
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <stdint.h>
+
+#define FLVF_HEADER 1
+#define FLVF_SCRIPT 2
+
+struct flvhdr
+{
+ char fh_magic[3];
+ char fh_version;
+ char fh_flags;
+ char fh_hlen[4];
+ char fh_pads[4];
+}__attribute__((packed));
+
+struct taghdr
+{
+ uint8_t th_type;
+ uint8_t th_dlen[3];
+ uint8_t th_tstamp[3];
+ uint8_t th_xstamp;
+ uint8_t th_streamid[3];
+}__attribute__((packed));
+
+struct flvcombine
+{
+ FILE * fc_file;
+ uint32_t fc_flags;
+ uint32_t fc_timestamp;
+ uint32_t fc_filesize;
+ double fc_duration;
+ int fc_filesize_offset;
+ int fc_duration_offset;
+};
+
+/* duration, filesize */
+
+uint32_t buftoint(const void *buf, size_t len)
+{
+ uint32_t bufint = 0;
+ const uint8_t *pval = (const uint8_t *)buf;
+ while (len-- > 0)
+ bufint = (bufint << 8) + *pval++;
+ return bufint;
+}
+
+int dd_copy(FILE * dst_fp, FILE * src_fp, size_t dlen)
+{
+ size_t len;
+ char buf[64 * 1024];
+ while (dlen > 0 && !feof(src_fp)) {
+ len = fread(buf, 1, dlen < sizeof(buf)? dlen: sizeof(buf), src_fp);
+ if (fwrite(buf, 1, len, dst_fp) != len)
+ break;
+ dlen -= len;
+ }
+ return dlen;
+}
+
+void adjtimestamp(struct taghdr *header, uint32_t stampbase)
+{
+ uint32_t netval = 0;
+ uint32_t adjtime = stampbase;
+ adjtime += buftoint(&header->th_tstamp, sizeof(header->th_tstamp));
+ adjtime += (header->th_xstamp << 24);
+ header->th_xstamp = (adjtime >> 24);
+ header->th_tstamp[0] = (adjtime >> 16);
+ header->th_tstamp[1] = (adjtime >> 8);
+ header->th_tstamp[2] = (adjtime >> 0);
+}
+
+void update_metainfo(struct flvcombine *combine, FILE *fp, size_t dlen)
+{
+ int i;
+ size_t len;
+ char *pmem = NULL;
+ char buf[256 * 1024];
+ double duration = 0.0;
+ uint8_t duration_bytes[8];
+ printf("dlen: %d\n", dlen);
+ assert (dlen < (256 * 1024));
+
+ len = fread(buf, 1, dlen < sizeof(buf)? dlen: sizeof(buf), fp);
+ if (len == 0)
+ return;
+ pmem = (char *)memmem(buf, len, "duration", 8);
+ if (pmem == NULL || pmem + 17l - buf > len)
+ return;
+ memcpy(&duration_bytes, pmem + 9, 8);
+ for (i = 0; i < 4; i ++) {
+ uint8_t tmp = duration_bytes[i];
+ duration_bytes[i] = duration_bytes[7 - i];
+ duration_bytes[7 - i] = tmp;
+ }
+ memcpy(&duration, &duration_bytes, 8);
+ combine->fc_duration += duration;
+ if (combine->fc_flags & FLVF_SCRIPT)
+ return;
+ combine->fc_duration_offset =
+ combine->fc_filesize + (pmem + 9l - buf) + sizeof(struct taghdr);
+ pmem = (char *)memmem(buf, len, "filesize", 8);
+ if (pmem == NULL || pmem + 17l - buf > len)
+ return;
+ combine->fc_filesize_offset =
+ combine->fc_filesize + (pmem + 9l - buf) + sizeof(struct taghdr);
+}
+
+int addflv(struct flvcombine *combine, const char *path)
+{
+ int error = 0;
+ FILE *fp, *fout;
+ char magic[4];
+ long savepos;
+ size_t len, dlen, flags;
+ struct flvhdr header;
+ struct taghdr *last;
+ struct taghdr tagvideo;
+ struct taghdr tagaudio;
+ struct taghdr tagheader;
+
+ fp = fopen(path, "rb");
+ fout = combine->fc_file;
+ if (fp == NULL || fout == NULL)
+ return 0;
+
+ last = NULL;
+ memset(magic, 0, sizeof(magic));
+ memset(&tagvideo, 0, sizeof(tagvideo));
+ memset(&tagaudio, 0, sizeof(tagaudio));
+
+ if ( !fread(&header, sizeof(header), 1, fp) )
+ goto fail;
+
+ memcpy(magic, header.fh_magic, 3);
+ if ( strcmp("FLV", magic) )
+ goto fail;
+
+ if ((combine->fc_flags & FLVF_HEADER) == 0) {
+ fwrite(&header, sizeof(header), 1, fout);
+ combine->fc_filesize += sizeof(header);
+ combine->fc_flags |= FLVF_HEADER;
+ }
+
+ printf("magic: %s\n", magic);
+ printf("flags: 0x%02x\n", header.fh_flags);
+ printf("version: 0x%02x\n", header.fh_version);
+ printf("header len: %d\n", buftoint(header.fh_hlen, sizeof(header.fh_hlen)));
+
+ while (feof(fp) == 0) {
+ if ( !fread(&tagheader, sizeof(tagheader), 1, fp) )
+ goto fail;
+
+ dlen = buftoint(tagheader.th_dlen, sizeof(tagheader.th_dlen));
+
+ switch (tagheader.th_type)
+ {
+ case 0x09:
+ adjtimestamp(&tagheader, combine->fc_timestamp);
+ tagvideo = tagheader;
+ last = &tagvideo;
+ break;
+ case 0x08:
+ adjtimestamp(&tagheader, combine->fc_timestamp);
+ tagaudio = tagheader;
+ last = &tagaudio;
+ break;
+ default:
+ flags = combine->fc_flags;
+ savepos = ftell(fp);
+ if (savepos == -1)
+ goto fail;
+ savepos = (flags & FLVF_SCRIPT)? (savepos + dlen + 4): savepos;
+ update_metainfo(combine, fp, dlen);
+ combine->fc_flags |= FLVF_SCRIPT;
+ if ( fseek(fp, savepos, SEEK_SET) )
+ goto fail;
+ if (flags & FLVF_SCRIPT)
+ continue;
+ break;
+ }
+ fwrite(&tagheader, sizeof(tagheader), 1, fout);
+ combine->fc_filesize += sizeof(tagheader);
+ combine->fc_filesize += (dlen + 4);
+ if ( dd_copy(fout, fp, dlen + 4)) {
+ error = -__LINE__;
+ break;
+ }
+ }
+
+fail:
+ fclose(fp);
+ if (last == &tagvideo || last == &tagaudio) {
+ combine->fc_timestamp = buftoint(last->th_tstamp, sizeof(last->th_tstamp));
+ combine->fc_timestamp |= (last->th_xstamp << 24);
+ printf("time stamp: %d\n", combine->fc_timestamp);
+ }
+ return 0;
+}
+
+void fixedflv(struct flvcombine *context)
+{
+ int i;
+ double dblval = 0.0;
+ uint8_t dblbytes[8];
+ FILE *fout = context->fc_file;
+
+ if (context->fc_filesize_offset > 0) {
+ if ( fseek(fout, context->fc_filesize_offset, SEEK_SET) )
+ return;
+ dblval = context->fc_filesize;
+ memcpy(dblbytes, &dblval, 8);
+
+ for (i = 0; i < 4; i ++) {
+ uint8_t tmp = dblbytes[i];
+ dblbytes[i] = dblbytes[7 - i];
+ dblbytes[7 - i] = tmp;
+ }
+ fwrite(dblbytes, 8, 1, fout);
+ }
+
+ if (context->fc_duration_offset > 0) {
+ if ( fseek(fout, context->fc_duration_offset, SEEK_SET) )
+ return;
+ dblval = context->fc_duration;
+ memcpy(dblbytes, &dblval, 8);
+
+ for (i = 0; i < 4; i ++) {
+ uint8_t tmp = dblbytes[i];
+ dblbytes[i] = dblbytes[7 - i];
+ dblbytes[7 - i] = tmp;
+ }
+ fwrite(dblbytes, 8, 1, fout);
+ }
+}
+
+int main(int argc, char *argv[])
+{
+ int i;
+ struct flvcombine context;
+ memset(&context, 0, sizeof(context));
+ context.fc_file = fopen("out.flv", "wb");
+ if (context.fc_file == NULL)
+ return -1;
+ context.fc_duration = 0;
+ for (i = 1; i < argc; i++)
+ addflv(&context, argv[i]);
+ fixedflv(&context);
+ fclose(context.fc_file);
+
+ printf("seconds: %d\n", context.fc_timestamp);
+ return 0;
+}