diff options
Diffstat (limited to 'a.c')
| -rw-r--r-- | a.c | 254 |
1 files changed, 254 insertions, 0 deletions
@@ -0,0 +1,254 @@ +#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; +} |