PR #20801 opened by paper URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20801 Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20801.patch
Before, this code would unnecessarily waste quite a bit of memory reading the entire file in, and in many cases just freeing the result and throwing it out anyway. This commit changes the behavior to use libopenmpt's callback structure. This is much more memory efficient, especially for particularly large files. Both pre-0.3.0 and post-0.3.0 preprocessor branches have been tested working with a plain amiga-style 'M.K.' module in ffplay. Signed-off-by: Paper <[email protected]> >From 81787bbaa31733ad7c5dd2ea727bc7bd06104719 Mon Sep 17 00:00:00 2001 From: Paper <[email protected]> Date: Tue, 2 Sep 2025 10:34:14 -0400 Subject: [PATCH] avformat/libopenmpt: implement file reading callbacks Before, this code would unnecessarily waste quite a bit of memory reading the entire file in, and in many cases just freeing the result and throwing it out anyway. This commit changes the behavior to use libopenmpt's callback structure. This is much more memory efficient, especially for particularly large files. Both pre-0.3.0 and post-0.3.0 preprocessor branches have been tested working with a plain amiga-style 'M.K.' module in ffplay. Signed-off-by: Paper <[email protected]> --- libavformat/libopenmpt.c | 66 ++++++++++++++++++++++++++++------------ 1 file changed, 47 insertions(+), 19 deletions(-) diff --git a/libavformat/libopenmpt.c b/libavformat/libopenmpt.c index 46af4bff22..52f4ab2b7d 100644 --- a/libavformat/libopenmpt.c +++ b/libavformat/libopenmpt.c @@ -69,6 +69,51 @@ static void openmpt_logfunc(const char *message, void *userdata) av_log(userdata, level, "%s\n", message); } +static size_t av_openmpt_read(void *stream, void *dst, size_t bytes) +{ + AVIOContext *ioctx = stream; + int r; + + /* avio_read takes an int, cap the size accordingly */ + if (bytes > (size_t)INT_MAX) + bytes = (size_t)INT_MAX; + + r = avio_read(ioctx, dst, bytes); + + return (r >= 0) ? r : 0; +} + +static int av_openmpt_seek(void *stream, int64_t offset, int whence) +{ + AVIOContext *ioctx = stream; + int whence_av; + + switch (whence) { + case OPENMPT_STREAM_SEEK_SET: whence_av = SEEK_SET; break; + case OPENMPT_STREAM_SEEK_CUR: whence_av = SEEK_CUR; break; + case OPENMPT_STREAM_SEEK_END: whence_av = SEEK_END; break; + /* invalid value, punt */ + default: return -1; + } + + /* openmpt expects stdio-style seek; don't return new position */ + return (avio_seek(ioctx, offset, whence_av) < 0) ? -1 : 0; +} + +static int64_t av_openmpt_tell(void *stream) +{ + AVIOContext *ioctx = stream; + int64_t r = avio_tell(ioctx); + + return (r < 0) ? -1 : r; +} + +static const openmpt_stream_callbacks openmpt_cbs = { + av_openmpt_read, + av_openmpt_seek, + av_openmpt_tell +}; + #define add_meta(s, name, meta) \ do { \ const char *value = meta; \ @@ -81,30 +126,14 @@ static int read_header_openmpt(AVFormatContext *s) { AVStream *st; OpenMPTContext *openmpt = s->priv_data; - int64_t size; - char *buf; #if OPENMPT_API_VERSION_AT_LEAST(0,3,0) int error; #endif int ret; - size = avio_size(s->pb); - if (size <= 0) - return AVERROR_INVALIDDATA; - buf = av_malloc(size); - if (!buf) - return AVERROR(ENOMEM); - size = avio_read(s->pb, buf, size); - if (size < 0) { - av_log(s, AV_LOG_ERROR, "Reading input buffer failed.\n"); - av_freep(&buf); - return size; - } - #if OPENMPT_API_VERSION_AT_LEAST(0,3,0) error = OPENMPT_ERROR_OK; - openmpt->module = openmpt_module_create_from_memory2(buf, size, openmpt_logfunc, s, NULL, NULL, &error, NULL, NULL); - av_freep(&buf); + openmpt->module = openmpt_module_create2(openmpt_cbs, s->pb, openmpt_logfunc, s, NULL, NULL, &error, NULL, NULL); if (!openmpt->module) { if (error == OPENMPT_ERROR_OUT_OF_MEMORY) return AVERROR(ENOMEM); @@ -114,8 +143,7 @@ static int read_header_openmpt(AVFormatContext *s) return AVERROR_UNKNOWN; } #else - openmpt->module = openmpt_module_create_from_memory(buf, size, openmpt_logfunc, s, NULL); - av_freep(&buf); + openmpt->module = openmpt_module_create(openmpt_cbs, s->pb, openmpt_logfunc, s, NULL); if (!openmpt->module) return AVERROR_INVALIDDATA; #endif -- 2.49.1 _______________________________________________ ffmpeg-devel mailing list -- [email protected] To unsubscribe send an email to [email protected]
