From a2a0b9e0da14b6e82aa783535ec1878c8ffbede0 Mon Sep 17 00:00:00 2001 From: Alex Agranovsky Date: Tue, 24 Nov 2015 00:06:14 -0500 Subject: [PATCH 1/2] Allow mpjpeg demuxer to process MIME parts which do not include Content-Length header. Fixes ticket 5023 Signed-off-by: Alex Agranovsky --- libavformat/mpjpegdec.c | 176 ++++++++++++++++++++++++++++++++++++------------ 1 file changed, 133 insertions(+), 43 deletions(-) diff --git a/libavformat/mpjpegdec.c b/libavformat/mpjpegdec.c index 2749a48..e494f1a 100644 --- a/libavformat/mpjpegdec.c +++ b/libavformat/mpjpegdec.c @@ -23,22 +23,16 @@ #include "avformat.h" #include "internal.h" +#include "avio_internal.h" -static int get_line(AVIOContext *pb, char *line, int line_size) -{ - int i = ff_get_line(pb, line, line_size); - if (i > 1 && line[i - 2] == '\r') - line[i - 2] = '\0'; - if (pb->error) - return pb->error; - - if (pb->eof_reached) - return AVERROR_EOF; - - return 0; -} +/** Context for demuxing an MPJPEG stream. */ +typedef struct MPJPEGDemuxContext { + char* boundary; + char* searchstr; + int searchstr_len; +} MPJPEGDemuxContext; static void trim_right(char* p) @@ -46,13 +40,32 @@ static void trim_right(char* p) char *end; if (!p || !*p) return; - end = p + strlen(p) - 1; - while (end != p && av_isspace(*end)) { + int len = strlen(p); + if ( !len ) + return; + end = p + len - 1; + while (end >= p && av_isspace(*end)) { *end = '\0'; end--; } } +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; @@ -86,12 +99,24 @@ static int split_tag_value(char **tag, char **value, char *line) return 0; } -static int parse_multipart_header(AVIOContext *pb, void *log_ctx); +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(AVProbeData *p) { AVIOContext *pb; int ret = 0; + int size = 0; if (p->buf_size < 2 || p->buf[0] != '-' || p->buf[1] != '-') return 0; @@ -100,7 +125,7 @@ static int mpjpeg_read_probe(AVProbeData *p) if (!pb) return 0; - ret = (parse_multipart_header(pb, NULL)>0)?AVPROBE_SCORE_MAX:0; + ret = ( parse_multipart_header(pb, &size, "--", NULL) > 0 ) ? AVPROBE_SCORE_MAX : 0; av_free(pb); @@ -110,17 +135,19 @@ static int mpjpeg_read_probe(AVProbeData *p) static int mpjpeg_read_header(AVFormatContext *s) { AVStream *st; - char boundary[70 + 2 + 1]; + 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]); - ret = get_line(s->pb, boundary, sizeof(boundary)); - if (ret < 0) - return ret; - - if (strncmp(boundary, "--", 2)) + if (strncmp(boundary, "--", 2)) { return AVERROR_INVALIDDATA; + } st = avformat_new_stream(s, NULL); if (!st) @@ -147,28 +174,44 @@ static int parse_content_length(const char *value) return val; } -static int parse_multipart_header(AVIOContext *pb, void *log_ctx) +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; + int ret; + + *size = -1; // get the CRLF as empty string ret = get_line(pb, line, sizeof(line)); - if (ret < 0) + if (ret < 0) { return ret; + } /* some implementation do not provide the required * initial CRLF (see rfc1341 7.2.1) */ - if (!line[0]) { + while (!line[0]) { ret = get_line(pb, line, sizeof(line)); - if (ret < 0) + if (ret < 0) { return ret; + } } - if (strncmp(line, "--", 2)) + if ( strncmp(line, expected_boundary, strlen(expected_boundary) ) ) { + if (log_ctx) { + av_log(log_ctx, + AV_LOG_ERROR, + "Expected boundary '%s' not found, instead found a line of %lu bytes\n", + expected_boundary, + strlen(line) ); + } + return AVERROR_INVALIDDATA; + } while (!pb->eof_reached) { char *tag, *value; @@ -201,32 +244,77 @@ static int parse_multipart_header(AVIOContext *pb, void *log_ctx) } else found_content_type = 1; } else if (!av_strcasecmp(tag, "Content-Length")) { - size = parse_content_length(value); - if (size < 0) - return size; + *size = parse_content_length(value); } } - if (!found_content_type || size < 0) { - return AVERROR_INVALIDDATA; - } - - return size; + return (found_content_type) ? 0 : AVERROR_INVALIDDATA; } + static int mpjpeg_read_packet(AVFormatContext *s, AVPacket *pkt) { - int ret; - int size = parse_multipart_header(s->pb, s); + int size; + MPJPEGDemuxContext *mpjpeg = s->priv_data; + if ( mpjpeg->boundary == NULL ) { + mpjpeg->boundary = av_strdup("--"); + mpjpeg->searchstr = av_strdup("\r\n--"); + mpjpeg->searchstr_len = strlen( mpjpeg->searchstr ); + } + + int ret = parse_multipart_header(s->pb, + &size, + mpjpeg->boundary, + s); - if (size < 0) - return size; - ret = av_get_packet(s->pb, pkt, size); if (ret < 0) return ret; - return 0; + 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 */ + + const int read_chunk = 2048; + av_init_packet(pkt); + pkt->data = NULL; + pkt->size = 0; + pkt->pos = avio_tell(s->pb); + + /* we may need to return as much as all we've read back to the buffer */ + ffio_ensure_seekback( s->pb, read_chunk ); + + + int remaining = 0, len; + + while ( ( ret = av_append_packet( s->pb, pkt, read_chunk - remaining ) ) >= 0 ) { + /* scan the new data */ + len = ret + remaining; + char* 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-2), SEEK_CUR ); + pkt->size -= (len-2); + return pkt->size; + } + len--; + start++; + } while ( len >= mpjpeg->searchstr_len ); + remaining = len; + } + + /* error or EOF occurred */ + if ( ret == AVERROR_EOF ) { + ret = ( pkt->size > 0 ) ? pkt->size : AVERROR_EOF; + } else { + av_packet_unref(pkt); + } + } + + return ret; } AVInputFormat ff_mpjpeg_demuxer = { @@ -234,7 +322,9 @@ AVInputFormat ff_mpjpeg_demuxer = { .long_name = NULL_IF_CONFIG_SMALL("MIME multipart JPEG"), .mime_type = "multipart/x-mixed-replace", .extensions = "mjpg", + .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 }; -- 2.4.9 (Apple Git-60)