| /* | |
| * Multipart JPEG format | |
| * Copyright (c) 2015 Luca Barbato | |
| * | |
| * 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 "libavutil/avstring.h" | |
| #include "libavutil/opt.h" | |
| #include "avformat.h" | |
| #include "demux.h" | |
| #include "internal.h" | |
| #include "avio_internal.h" | |
| typedef struct MPJPEGDemuxContext { | |
| const AVClass *class; | |
| char *boundary; | |
| char *searchstr; | |
| int searchstr_len; | |
| int strict_mime_boundary; | |
| } MPJPEGDemuxContext; | |
| static void trim_right(char *p) | |
| { | |
| char *end; | |
| if (!p || !*p) | |
| return; | |
| end = p + strlen(p); | |
| while (end > p && av_isspace(*(end-1))) | |
| *(--end) = '\0'; | |
| } | |
| static int get_line(AVIOContext *pb, char *line, int line_size) | |
| { | |
| ff_get_line(pb, line, line_size); | |
| if (pb->error) | |
| return pb->error; | |
| if (pb->eof_reached) | |
| return AVERROR_EOF; | |
| trim_right(line); | |
| return 0; | |
| } | |
| static int split_tag_value(char **tag, char **value, char *line) | |
| { | |
| char *p = line; | |
| int foundData = 0; | |
| *tag = NULL; | |
| *value = NULL; | |
| while (*p != '\0' && *p != ':') { | |
| if (!av_isspace(*p)) { | |
| foundData = 1; | |
| } | |
| p++; | |
| } | |
| if (*p != ':') | |
| return foundData ? AVERROR_INVALIDDATA : 0; | |
| *p = '\0'; | |
| *tag = line; | |
| trim_right(*tag); | |
| p++; | |
| while (av_isspace(*p)) | |
| p++; | |
| *value = p; | |
| trim_right(*value); | |
| return 0; | |
| } | |
| static int parse_multipart_header(AVIOContext *pb, | |
| int* size, | |
| const char* expected_boundary, | |
| void *log_ctx); | |
| static int mpjpeg_read_close(AVFormatContext *s) | |
| { | |
| MPJPEGDemuxContext *mpjpeg = s->priv_data; | |
| av_freep(&mpjpeg->boundary); | |
| av_freep(&mpjpeg->searchstr); | |
| return 0; | |
| } | |
| static int mpjpeg_read_probe(const AVProbeData *p) | |
| { | |
| FFIOContext pb; | |
| int ret = 0; | |
| int size = 0; | |
| if (p->buf_size < 2 || p->buf[0] != '-' || p->buf[1] != '-') | |
| return 0; | |
| ffio_init_read_context(&pb, p->buf, p->buf_size); | |
| ret = (parse_multipart_header(&pb.pub, &size, "--", NULL) >= 0) ? AVPROBE_SCORE_MAX : 0; | |
| return ret; | |
| } | |
| static int mpjpeg_read_header(AVFormatContext *s) | |
| { | |
| AVStream *st; | |
| char boundary[70 + 2 + 1] = {0}; | |
| int64_t pos = avio_tell(s->pb); | |
| int ret; | |
| do { | |
| ret = get_line(s->pb, boundary, sizeof(boundary)); | |
| if (ret < 0) | |
| return ret; | |
| } while (!boundary[0]); | |
| if (strncmp(boundary, "--", 2)) | |
| return AVERROR_INVALIDDATA; | |
| st = avformat_new_stream(s, NULL); | |
| if (!st) | |
| return AVERROR(ENOMEM); | |
| st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; | |
| st->codecpar->codec_id = AV_CODEC_ID_MJPEG; | |
| avpriv_set_pts_info(st, 60, 1, 25); | |
| avio_seek(s->pb, pos, SEEK_SET); | |
| return 0; | |
| } | |
| static int parse_content_length(const char *value) | |
| { | |
| long int val = strtol(value, NULL, 10); | |
| if (val == LONG_MIN || val == LONG_MAX) | |
| return AVERROR(errno); | |
| if (val > INT_MAX) | |
| return AVERROR(ERANGE); | |
| return val; | |
| } | |
| static int parse_multipart_header(AVIOContext *pb, | |
| int* size, | |
| const char* expected_boundary, | |
| void *log_ctx) | |
| { | |
| char line[128]; | |
| int found_content_type = 0; | |
| int ret; | |
| *size = -1; | |
| // get the CRLF as empty string | |
| ret = get_line(pb, line, sizeof(line)); | |
| if (ret < 0) | |
| return ret; | |
| /* some implementation do not provide the required | |
| * initial CRLF (see rfc1341 7.2.1) | |
| */ | |
| while (!line[0]) { | |
| ret = get_line(pb, line, sizeof(line)); | |
| if (ret < 0) | |
| return ret; | |
| } | |
| if (!av_strstart(line, expected_boundary, NULL)) { | |
| if (log_ctx) | |
| av_log(log_ctx, | |
| AV_LOG_ERROR, | |
| "Expected boundary '%s' not found, instead found a line of %"SIZE_SPECIFIER" bytes\n", | |
| expected_boundary, | |
| strlen(line)); | |
| return AVERROR_INVALIDDATA; | |
| } | |
| while (!pb->eof_reached) { | |
| char *tag, *value; | |
| ret = get_line(pb, line, sizeof(line)); | |
| if (ret < 0) { | |
| if (ret == AVERROR_EOF) | |
| break; | |
| return ret; | |
| } | |
| if (line[0] == '\0') | |
| break; | |
| ret = split_tag_value(&tag, &value, line); | |
| if (ret < 0) | |
| return ret; | |
| if (value==NULL || tag==NULL) | |
| break; | |
| if (!av_strcasecmp(tag, "Content-type")) { | |
| if (av_strcasecmp(value, "image/jpeg")) { | |
| if (log_ctx) | |
| av_log(log_ctx, AV_LOG_ERROR, | |
| "Unexpected %s : %s\n", | |
| tag, value); | |
| return AVERROR_INVALIDDATA; | |
| } else | |
| found_content_type = 1; | |
| } else if (!av_strcasecmp(tag, "Content-Length")) { | |
| *size = parse_content_length(value); | |
| if ( *size < 0 ) | |
| if (log_ctx) | |
| av_log(log_ctx, AV_LOG_WARNING, | |
| "Invalid Content-Length value : %s\n", | |
| value); | |
| } | |
| } | |
| return found_content_type ? 0 : AVERROR_INVALIDDATA; | |
| } | |
| static char* mpjpeg_get_boundary(AVIOContext* pb) | |
| { | |
| uint8_t *mime_type = NULL; | |
| const char *start; | |
| const char *end; | |
| uint8_t *res = NULL; | |
| int len; | |
| /* get MIME type, and skip to the first parameter */ | |
| av_opt_get(pb, "mime_type", AV_OPT_SEARCH_CHILDREN, &mime_type); | |
| start = mime_type; | |
| while (start != NULL && *start != '\0') { | |
| start = strchr(start, ';'); | |
| if (!start) | |
| break; | |
| start = start+1; | |
| while (av_isspace(*start)) | |
| start++; | |
| if (av_stristart(start, "boundary=", &start)) { | |
| end = strchr(start, ';'); | |
| if (end) | |
| len = end - start - 1; | |
| else | |
| len = strlen(start); | |
| /* some endpoints may enclose the boundary | |
| in Content-Type in quotes */ | |
| if ( len>2 && *start == '"' && start[len-1] == '"' ) { | |
| start++; | |
| len -= 2; | |
| } | |
| res = av_strndup(start, len); | |
| break; | |
| } | |
| } | |
| av_freep(&mime_type); | |
| return res; | |
| } | |
| static int mpjpeg_read_packet(AVFormatContext *s, AVPacket *pkt) | |
| { | |
| int size; | |
| int ret; | |
| MPJPEGDemuxContext *mpjpeg = s->priv_data; | |
| if (mpjpeg->boundary == NULL) { | |
| uint8_t* boundary = NULL; | |
| if (mpjpeg->strict_mime_boundary) { | |
| boundary = mpjpeg_get_boundary(s->pb); | |
| } | |
| if (boundary != NULL) { | |
| mpjpeg->boundary = av_asprintf("--%s", boundary); | |
| mpjpeg->searchstr = av_asprintf("\r\n--%s\r\n", boundary); | |
| av_freep(&boundary); | |
| } else { | |
| mpjpeg->boundary = av_strdup("--"); | |
| mpjpeg->searchstr = av_strdup("\r\n--"); | |
| } | |
| if (!mpjpeg->boundary || !mpjpeg->searchstr) { | |
| av_freep(&mpjpeg->boundary); | |
| av_freep(&mpjpeg->searchstr); | |
| return AVERROR(ENOMEM); | |
| } | |
| mpjpeg->searchstr_len = strlen(mpjpeg->searchstr); | |
| } | |
| ret = parse_multipart_header(s->pb, &size, mpjpeg->boundary, s); | |
| if (ret < 0) | |
| return ret; | |
| if (size > 0) { | |
| /* size has been provided to us in MIME header */ | |
| ret = av_get_packet(s->pb, pkt, size); | |
| } else { | |
| /* no size was given -- we read until the next boundary or end-of-file */ | |
| int len; | |
| const int read_chunk = 2048; | |
| pkt->pos = avio_tell(s->pb); | |
| while ((ret = ffio_ensure_seekback(s->pb, read_chunk)) >= 0 && /* we may need to return as much as all we've read back to the buffer */ | |
| (ret = av_append_packet(s->pb, pkt, read_chunk)) >= 0) { | |
| /* scan the new data */ | |
| char *start; | |
| len = ret; | |
| start = pkt->data + pkt->size - len; | |
| do { | |
| if (!memcmp(start, mpjpeg->searchstr, mpjpeg->searchstr_len)) { | |
| // got the boundary! rewind the stream | |
| avio_seek(s->pb, -len, SEEK_CUR); | |
| pkt->size -= len; | |
| return pkt->size; | |
| } | |
| len--; | |
| start++; | |
| } while (len >= mpjpeg->searchstr_len); | |
| avio_seek(s->pb, -len, SEEK_CUR); | |
| pkt->size -= len; | |
| } | |
| /* error or EOF occurred */ | |
| if (ret == AVERROR_EOF) { | |
| ret = pkt->size > 0 ? pkt->size : AVERROR_EOF; | |
| } | |
| } | |
| return ret; | |
| } | |
| #define OFFSET(x) offsetof(MPJPEGDemuxContext, x) | |
| #define DEC AV_OPT_FLAG_DECODING_PARAM | |
| static const AVOption mpjpeg_options[] = { | |
| { "strict_mime_boundary", "require MIME boundaries match", OFFSET(strict_mime_boundary), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC }, | |
| { NULL } | |
| }; | |
| static const AVClass mpjpeg_demuxer_class = { | |
| .class_name = "MPJPEG demuxer", | |
| .item_name = av_default_item_name, | |
| .option = mpjpeg_options, | |
| .version = LIBAVUTIL_VERSION_INT, | |
| }; | |
| const FFInputFormat ff_mpjpeg_demuxer = { | |
| .p.name = "mpjpeg", | |
| .p.long_name = NULL_IF_CONFIG_SMALL("MIME multipart JPEG"), | |
| .p.mime_type = "multipart/x-mixed-replace", | |
| .p.extensions = "mjpg", | |
| .p.priv_class = &mpjpeg_demuxer_class, | |
| .p.flags = AVFMT_NOTIMESTAMPS, | |
| .priv_data_size = sizeof(MPJPEGDemuxContext), | |
| .read_probe = mpjpeg_read_probe, | |
| .read_header = mpjpeg_read_header, | |
| .read_packet = mpjpeg_read_packet, | |
| .read_close = mpjpeg_read_close, | |
| }; |