X-Git-Url: https://rtime.felk.cvut.cz/gitweb/frescor/ffmpeg.git/blobdiff_plain/aa2878705d88fd0f5cbe711e479f32e50e5bbe94..77b0842e4959363e840f573192cccd6e4ac40cb9:/libavformat/aviobuf.c

diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c
index 866641ad0..1dac20298 100644
--- a/libavformat/aviobuf.c
+++ b/libavformat/aviobuf.c
@@ -18,9 +18,14 @@
  * 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/crc.h"
+#include "libavutil/intreadwrite.h"
 #include "avformat.h"
 #include "avio.h"
 #include <stdarg.h>
+#include <unistd.h>
+#include <malloc.h>
 
 #define IO_BUFFER_SIZE 32768
 
@@ -33,17 +38,13 @@ int init_put_byte(ByteIOContext *s,
                   void *opaque,
                   int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
                   int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
-                  offset_t (*seek)(void *opaque, offset_t offset, int whence))
+                  int64_t (*seek)(void *opaque, int64_t offset, int whence))
 {
     s->buffer = buffer;
     s->buffer_size = buffer_size;
     s->buf_ptr = buffer;
-    s->write_flag = write_flag;
-    if (!s->write_flag)
-        s->buf_end = buffer;
-    else
-        s->buf_end = buffer + buffer_size;
     s->opaque = opaque;
+    url_resetbuf(s, write_flag ? URL_WRONLY : URL_RDONLY);
     s->write_packet = write_packet;
     s->read_packet = read_packet;
     s->seek = seek;
@@ -58,11 +59,73 @@ int init_put_byte(ByteIOContext *s,
         s->pos = buffer_size;
         s->buf_end = s->buffer + buffer_size;
     }
+    s->read_pause = NULL;
+    s->read_seek  = NULL;
     return 0;
 }
 
+ByteIOContext *av_alloc_put_byte(
+                  unsigned char *buffer,
+                  int buffer_size,
+                  int write_flag,
+                  void *opaque,
+                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
+                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
+                  int64_t (*seek)(void *opaque, int64_t offset, int whence))
+{
+    ByteIOContext *s = av_mallocz(sizeof(ByteIOContext));
+    init_put_byte(s, buffer, buffer_size, write_flag, opaque,
+                  read_packet, write_packet, seek);
+    return s;
+}
+
+#define BLOCK_SIZE 512
+
+static void flush_buffer_o_direct(ByteIOContext *s)
+{
+    size_t data_len = s->buf_ptr - s->buffer;
+
+    /* Write all data in the buffer to the disk together with any
+     * additional space at the end of the buffer up to the first
+     * multiple of BLOCK_SIZE. The last block is always written to the
+     * disk despite not being fully filled. If the last block is not
+     * fully filled, we keep it (moved to the begginig of the buffer)
+     * and any subsequent call to this function will rewrite the block
+     * together with the additional data added to the buffer. */
+    size_t to_write = (data_len + BLOCK_SIZE - 1) & ~(BLOCK_SIZE - 1);
+    size_t whole_blocks = data_len & ~(BLOCK_SIZE - 1);
+    int64_t res = AVERROR(EPIPE);
+    if (data_len > 0) {
+        if (s->write_packet && !s->error){
+            int ret= s->write_packet(s->opaque, s->buffer, to_write);
+            if(ret < 0){
+                s->error = ret;
+            }
+        }
+        if(s->update_checksum){
+	    av_log(NULL, AV_LOG_ERROR, "Checksumming not implemented in O_DIRECT patch\n");
+            s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
+            s->checksum_ptr= s->buffer;
+        }
+        s->pos += to_write;
+	memcpy(s->buffer, &s->buffer[whole_blocks], data_len - whole_blocks);
+	s->buf_ptr -= whole_blocks;
+
+        if (s->seek)
+	    res = s->seek(s->opaque, s->pos - to_write + whole_blocks, SEEK_SET);
+	if (res < 0)
+	    av_log(NULL, AV_LOG_ERROR, "seek error inside %s: %lld\n", __func__, res);
+	//av_log(NULL, AV_LOG_ERROR, "ZZZ tw=%zu, pos=%zd\n", to_write, s->pos);
+    }
+}
+
 static void flush_buffer(ByteIOContext *s)
 {
+    av_log(NULL, AV_LOG_ERROR, "WRITE %p: pos=%zd len=%zd\n", s, s->pos, s->buf_ptr - s->buffer);
+    if (s->o_direct_flag) {
+	flush_buffer_o_direct(s);
+	return;
+    }
     if (s->buf_ptr > s->buffer) {
         if (s->write_packet && !s->error){
             int ret= s->write_packet(s->opaque, s->buffer, s->buf_ptr - s->buffer);
@@ -111,13 +174,18 @@ void put_flush_packet(ByteIOContext *s)
     s->must_flush = 0;
 }
 
-offset_t url_fseek(ByteIOContext *s, offset_t offset, int whence)
+int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence)
 {
-    offset_t offset1;
-    offset_t pos= s->pos - (s->write_flag ? 0 : (s->buf_end - s->buffer));
+    int64_t offset1;
+    int64_t pos;
+
+    if(!s)
+        return AVERROR(EINVAL);
+
+    pos = s->pos - (s->write_flag ? 0 : (s->buf_end - s->buffer));
 
     if (whence != SEEK_CUR && whence != SEEK_SET)
-        return -EINVAL;
+        return AVERROR(EINVAL);
 
     if (whence == SEEK_CUR) {
         offset1 = pos + (s->buf_ptr - s->buffer);
@@ -125,67 +193,87 @@ offset_t url_fseek(ByteIOContext *s, offset_t offset, int whence)
             return offset1;
         offset += offset1;
     }
+    //if (s->o_direct_flag)
+    av_log(NULL, AV_LOG_ERROR, "SEEK  %p: from %llu to %llu\n", s, pos, offset);
+
     offset1 = offset - pos;
     if (!s->must_flush &&
-        offset1 >= 0 && offset1 < (s->buf_end - s->buffer)) {
+        offset1 >= 0 && offset1 <= (s->buf_end - s->buffer)) {
         /* can do the seek inside the buffer */
         s->buf_ptr = s->buffer + offset1;
+	if (s->o_direct_flag)
+	    av_log(NULL, AV_LOG_ERROR, "Internal seek by %llu\n", offset1);
     } else if(s->is_streamed && !s->write_flag &&
               offset1 >= 0 && offset1 < (s->buf_end - s->buffer) + (1<<16)){
         while(s->pos < offset && !s->eof_reached)
             fill_buffer(s);
+        if (s->eof_reached)
+            return AVERROR(EPIPE);
         s->buf_ptr = s->buf_end + offset - s->pos;
     } else {
-#if defined(CONFIG_MUXERS) || defined(CONFIG_NETWORK)
+        int64_t res = AVERROR(EPIPE);
+
+#if CONFIG_MUXERS || CONFIG_NETWORK
         if (s->write_flag) {
             flush_buffer(s);
             s->must_flush = 1;
-        } else
-#endif /* defined(CONFIG_MUXERS) || defined(CONFIG_NETWORK) */
-        {
-            s->buf_end = s->buffer;
         }
+#endif /* CONFIG_MUXERS || CONFIG_NETWORK */
+#warning TODO read the whole block from the file to the buffer
+        if (!s->seek || (res = s->seek(s->opaque, offset, SEEK_SET)) < 0)
+            return res;
+        if (!s->write_flag)
+            s->buf_end = s->buffer;
         s->buf_ptr = s->buffer;
-        if (!s->seek || s->seek(s->opaque, offset, SEEK_SET) == (offset_t)-EPIPE)
-            return -EPIPE;
         s->pos = offset;
     }
     s->eof_reached = 0;
     return offset;
 }
 
-void url_fskip(ByteIOContext *s, offset_t offset)
+void url_fskip(ByteIOContext *s, int64_t offset)
 {
     url_fseek(s, offset, SEEK_CUR);
 }
 
-offset_t url_ftell(ByteIOContext *s)
+int64_t url_ftell(ByteIOContext *s)
 {
     return url_fseek(s, 0, SEEK_CUR);
 }
 
-offset_t url_fsize(ByteIOContext *s)
+int64_t url_fsize(ByteIOContext *s)
 {
-    offset_t size;
+    int64_t size;
+
+    if(!s)
+        return AVERROR(EINVAL);
 
     if (!s->seek)
-        return -EPIPE;
-    size = s->seek(s->opaque, -1, SEEK_END) + 1;
-    s->seek(s->opaque, s->pos, SEEK_SET);
+        return AVERROR(EPIPE);
+    size = s->seek(s->opaque, 0, AVSEEK_SIZE);
+    if(size<0){
+        if ((size = s->seek(s->opaque, -1, SEEK_END)) < 0)
+            return size;
+        size++;
+        s->seek(s->opaque, s->pos, SEEK_SET);
+    }
     return size;
 }
 
 int url_feof(ByteIOContext *s)
 {
+    if(!s)
+        return 0;
     return s->eof_reached;
 }
 
 int url_ferror(ByteIOContext *s)
 {
+    if(!s)
+        return 0;
     return s->error;
 }
 
-#if defined(CONFIG_MUXERS) || defined(CONFIG_PROTOCOLS)
 void put_le32(ByteIOContext *s, unsigned int val)
 {
     put_byte(s, val);
@@ -252,45 +340,60 @@ void put_tag(ByteIOContext *s, const char *tag)
         put_byte(s, *tag++);
     }
 }
-#endif //CONFIG_MUXERS || CONFIG_PROTOCOLS
 
 /* Input stream */
 
 static void fill_buffer(ByteIOContext *s)
 {
-    int len;
+    uint8_t *dst= !s->max_packet_size && s->buf_end - s->buffer < s->buffer_size ? s->buf_ptr : s->buffer;
+    int len= s->buffer_size - (dst - s->buffer);
+
+    assert(s->buf_ptr == s->buf_end);
 
     /* no need to do anything if EOF already reached */
     if (s->eof_reached)
         return;
 
-    if(s->update_checksum){
+    if(s->update_checksum && dst == s->buffer){
         if(s->buf_end > s->checksum_ptr)
             s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_end - s->checksum_ptr);
         s->checksum_ptr= s->buffer;
     }
 
-    len = s->read_packet(s->opaque, s->buffer, s->buffer_size);
+    if(s->read_packet)
+        len = s->read_packet(s->opaque, dst, len);
+    else
+        len = 0;
     if (len <= 0) {
         /* do not modify buffer if EOF reached so that a seek back can
            be done without rereading data */
         s->eof_reached = 1;
-    if(len<0)
-        s->error= len;
+        if(len<0)
+            s->error= len;
     } else {
         s->pos += len;
-        s->buf_ptr = s->buffer;
-        s->buf_end = s->buffer + len;
+        s->buf_ptr = dst;
+        s->buf_end = dst + len;
     }
 }
 
-unsigned long get_checksum(ByteIOContext *s){
+unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
+                                    unsigned int len)
+{
+    return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len);
+}
+
+unsigned long get_checksum(ByteIOContext *s)
+{
     s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
     s->update_checksum= NULL;
     return s->checksum;
 }
 
-void init_checksum(ByteIOContext *s, unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), unsigned long checksum){
+void init_checksum(ByteIOContext *s,
+                   unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
+                   unsigned long checksum)
+{
     s->update_checksum= update_checksum;
     if(s->update_checksum){
         s->checksum= checksum;
@@ -298,8 +401,6 @@ void init_checksum(ByteIOContext *s, unsigned long (*update_checksum)(unsigned l
     }
 }
 
-/* NOTE: return 0 if EOF, so you cannot use it if EOF handling is
-   necessary */
 /* XXX: put an inline version */
 int get_byte(ByteIOContext *s)
 {
@@ -314,7 +415,6 @@ int get_byte(ByteIOContext *s)
     }
 }
 
-/* NOTE: return URL_EOF (-1) if EOF */
 int url_fgetc(ByteIOContext *s)
 {
     if (s->buf_ptr < s->buf_end) {
@@ -339,7 +439,8 @@ int get_buffer(ByteIOContext *s, unsigned char *buf, int size)
             len = size;
         if (len == 0) {
             if(size > s->buffer_size && !s->update_checksum){
-                len = s->read_packet(s->opaque, buf, size);
+                if(s->read_packet)
+                    len = s->read_packet(s->opaque, buf, size);
                 if (len <= 0) {
                     /* do not modify buffer if EOF reached so that a seek back can
                     be done without rereading data */
@@ -467,32 +568,18 @@ uint64_t get_be64(ByteIOContext *s)
     return val;
 }
 
-/* link with avio functions */
-
-#ifdef CONFIG_MUXERS
-static int url_write_packet(void *opaque, uint8_t *buf, int buf_size)
-{
-    URLContext *h = opaque;
-    return url_write(h, buf, buf_size);
-}
-#else
-#define         url_write_packet NULL
-#endif //CONFIG_MUXERS
-
-static int url_read_packet(void *opaque, uint8_t *buf, int buf_size)
-{
-    URLContext *h = opaque;
-    return url_read(h, buf, buf_size);
-}
+uint64_t ff_get_v(ByteIOContext *bc){
+    uint64_t val = 0;
+    int tmp;
 
-static offset_t url_seek_packet(void *opaque, offset_t offset, int whence)
-{
-    URLContext *h = opaque;
-    return url_seek(h, offset, whence);
-    //return 0;
+    do{
+        tmp = get_byte(bc);
+        val= (val<<7) + (tmp&127);
+    }while(tmp&128);
+    return val;
 }
 
-int url_fdopen(ByteIOContext *s, URLContext *h)
+int url_fdopen(ByteIOContext **s, URLContext *h)
 {
     uint8_t *buffer;
     int buffer_size, max_packet_size;
@@ -504,47 +591,76 @@ int url_fdopen(ByteIOContext *s, URLContext *h)
     } else {
         buffer_size = IO_BUFFER_SIZE;
     }
-    buffer = av_malloc(buffer_size);
+    if (h->flags & URL_DIRECT) {
+	buffer_size = 2*buffer_size+BLOCK_SIZE;
+	buffer = memalign(sysconf(_SC_PAGESIZE), buffer_size);
+	;
+    } else {
+	buffer = av_malloc(buffer_size);
+    }
     if (!buffer)
-        return -ENOMEM;
+        return AVERROR(ENOMEM);
+
+    *s = av_mallocz(sizeof(ByteIOContext));
+    if(!*s) {
+        av_free(buffer);
+        return AVERROR(ENOMEM);
+    }
 
-    if (init_put_byte(s, buffer, buffer_size,
+    if (init_put_byte(*s, buffer, buffer_size,
                       (h->flags & URL_WRONLY || h->flags & URL_RDWR), h,
-                      url_read_packet, url_write_packet, url_seek_packet) < 0) {
+                      url_read, url_write, url_seek) < 0) {
         av_free(buffer);
-        return AVERROR_IO;
+        av_freep(s);
+        return AVERROR(EIO);
+    }
+    (*s)->is_streamed = h->is_streamed;
+    (*s)->max_packet_size = max_packet_size;
+    (*s)->o_direct_flag = !!(h->flags & URL_DIRECT);
+    if(h->prot) {
+        (*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause;
+        (*s)->read_seek  = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek;
     }
-    s->is_streamed = h->is_streamed;
-    s->max_packet_size = max_packet_size;
     return 0;
 }
 
-/* XXX: must be called before any I/O */
 int url_setbufsize(ByteIOContext *s, int buf_size)
 {
     uint8_t *buffer;
     buffer = av_malloc(buf_size);
     if (!buffer)
-        return -ENOMEM;
+        return AVERROR(ENOMEM);
 
     av_free(s->buffer);
     s->buffer = buffer;
     s->buffer_size = buf_size;
     s->buf_ptr = buffer;
-    if (!s->write_flag)
-        s->buf_end = buffer;
-    else
-        s->buf_end = buffer + buf_size;
+    url_resetbuf(s, s->write_flag ? URL_WRONLY : URL_RDONLY);
     return 0;
 }
 
-/* NOTE: when opened as read/write, the buffers are only used for
-   reading */
-int url_fopen(ByteIOContext *s, const char *filename, int flags)
+int url_resetbuf(ByteIOContext *s, int flags)
+{
+    URLContext *h = s->opaque;
+    if ((flags & URL_RDWR) || (h && h->flags != flags && !h->flags & URL_RDWR))
+        return AVERROR(EINVAL);
+
+    if (flags & URL_WRONLY) {
+        s->buf_end = s->buffer + s->buffer_size;
+        s->write_flag = 1;
+    } else {
+        s->buf_end = s->buffer;
+        s->write_flag = 0;
+    }
+    return 0;
+}
+
+int url_fopen(ByteIOContext **s, const char *filename, int flags)
 {
     URLContext *h;
     int err;
 
+    av_log(NULL, AV_LOG_ERROR, "%s: %p %s\n", __func__, s, filename);
     err = url_open(&h, filename, flags);
     if (err < 0)
         return err;
@@ -561,7 +677,7 @@ int url_fclose(ByteIOContext *s)
     URLContext *h = s->opaque;
 
     av_free(s->buffer);
-    memset(s, 0, sizeof(ByteIOContext));
+    av_free(s);
     return url_close(h);
 }
 
@@ -570,8 +686,7 @@ URLContext *url_fileno(ByteIOContext *s)
     return s->opaque;
 }
 
-#ifdef CONFIG_MUXERS
-/* XXX: currently size is limited */
+#if CONFIG_MUXERS
 int url_fprintf(ByteIOContext *s, const char *fmt, ...)
 {
     va_list ap;
@@ -586,8 +701,6 @@ int url_fprintf(ByteIOContext *s, const char *fmt, ...)
 }
 #endif //CONFIG_MUXERS
 
-/* note: unlike fgets, the EOL character is not returned and a whole
-   line is parsed. return NULL if first char read was EOF */
 char *url_fgets(ByteIOContext *s, char *buf, int buf_size)
 {
     int c;
@@ -609,31 +722,51 @@ char *url_fgets(ByteIOContext *s, char *buf, int buf_size)
     return buf;
 }
 
-/*
- * Return the maximum packet size associated to packetized buffered file
- * handle. If the file is not packetized (stream like http or file on
- * disk), then 0 is returned.
- *
- * @param h buffered file handle
- * @return maximum packet size in bytes
- */
 int url_fget_max_packet_size(ByteIOContext *s)
 {
     return s->max_packet_size;
 }
 
+int av_url_read_fpause(ByteIOContext *s, int pause)
+{
+    if (!s->read_pause)
+        return AVERROR(ENOSYS);
+    return s->read_pause(s->opaque, pause);
+}
+
+int64_t av_url_read_fseek(ByteIOContext *s, int stream_index,
+                          int64_t timestamp, int flags)
+{
+    URLContext *h = s->opaque;
+    int64_t ret;
+    if (!s->read_seek)
+        return AVERROR(ENOSYS);
+    ret = s->read_seek(h, stream_index, timestamp, flags);
+    if(ret >= 0) {
+        s->buf_ptr = s->buf_end; // Flush buffer
+        s->pos = s->seek(h, 0, SEEK_CUR);
+    }
+    return ret;
+}
+
 /* url_open_dyn_buf and url_close_dyn_buf are used in rtp.c to send a response
- * back to the server even if CONFIG_MUXERS is not set. */
-#if defined(CONFIG_MUXERS) || defined(CONFIG_NETWORK)
+ * back to the server even if CONFIG_MUXERS is false. */
+#if CONFIG_MUXERS || CONFIG_NETWORK
 /* buffer handling */
-int url_open_buf(ByteIOContext *s, uint8_t *buf, int buf_size, int flags)
+int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags)
 {
-    return init_put_byte(s, buf, buf_size,
-                         (flags & URL_WRONLY || flags & URL_RDWR),
-                         NULL, NULL, NULL, NULL);
+    int ret;
+    *s = av_mallocz(sizeof(ByteIOContext));
+    if(!*s)
+        return AVERROR(ENOMEM);
+    ret = init_put_byte(*s, buf, buf_size,
+                        (flags & URL_WRONLY || flags & URL_RDWR),
+                        NULL, NULL, NULL, NULL);
+    if(ret != 0)
+        av_freep(s);
+    return ret;
 }
 
-/* return the written or read size */
 int url_close_buf(ByteIOContext *s)
 {
     put_flush_packet(s);
@@ -652,7 +785,7 @@ typedef struct DynBuffer {
 static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
 {
     DynBuffer *d = opaque;
-    int new_size, new_allocated_size;
+    unsigned new_size, new_allocated_size;
 
     /* reallocate buffer if needed */
     new_size = d->pos + buf_size;
@@ -669,7 +802,7 @@ static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
     if (new_allocated_size > d->allocated_size) {
         d->buffer = av_realloc(d->buffer, new_allocated_size);
         if(d->buffer == NULL)
-             return -1234;
+             return AVERROR(ENOMEM);
         d->allocated_size = new_allocated_size;
     }
     memcpy(d->buffer + d->pos, buf, buf_size);
@@ -685,10 +818,7 @@ static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
     int ret;
 
     /* packetized write: output the header */
-    buf1[0] = (buf_size >> 24);
-    buf1[1] = (buf_size >> 16);
-    buf1[2] = (buf_size >> 8);
-    buf1[3] = (buf_size);
+    AV_WB32(buf1, buf_size);
     ret= dyn_buf_write(opaque, buf1, 4);
     if(ret < 0)
         return ret;
@@ -697,7 +827,7 @@ static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
     return dyn_buf_write(opaque, buf, buf_size);
 }
 
-static offset_t dyn_buf_seek(void *opaque, offset_t offset, int whence)
+static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
 {
     DynBuffer *d = opaque;
 
@@ -711,70 +841,48 @@ static offset_t dyn_buf_seek(void *opaque, offset_t offset, int whence)
     return 0;
 }
 
-static int url_open_dyn_buf_internal(ByteIOContext *s, int max_packet_size)
+static int url_open_dyn_buf_internal(ByteIOContext **s, int max_packet_size)
 {
     DynBuffer *d;
-    int io_buffer_size, ret;
-
-    if (max_packet_size)
-        io_buffer_size = max_packet_size;
-    else
-        io_buffer_size = 1024;
+    int ret;
+    unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
 
     if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
         return -1;
-    d = av_malloc(sizeof(DynBuffer) + io_buffer_size);
+    d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
     if (!d)
-        return -1;
+        return AVERROR(ENOMEM);
+    *s = av_mallocz(sizeof(ByteIOContext));
+    if(!*s) {
+        av_free(d);
+        return AVERROR(ENOMEM);
+    }
     d->io_buffer_size = io_buffer_size;
-    d->buffer = NULL;
-    d->pos = 0;
-    d->size = 0;
-    d->allocated_size = 0;
-    ret = init_put_byte(s, d->io_buffer, io_buffer_size,
+    ret = init_put_byte(*s, d->io_buffer, io_buffer_size,
                         1, d, NULL,
                         max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
                         max_packet_size ? NULL : dyn_buf_seek);
     if (ret == 0) {
-        s->max_packet_size = max_packet_size;
+        (*s)->max_packet_size = max_packet_size;
+    } else {
+        av_free(d);
+        av_freep(s);
     }
     return ret;
 }
 
-/*
- * Open a write only memory stream.
- *
- * @param s new IO context
- * @return zero if no error.
- */
-int url_open_dyn_buf(ByteIOContext *s)
+int url_open_dyn_buf(ByteIOContext **s)
 {
     return url_open_dyn_buf_internal(s, 0);
 }
 
-/*
- * Open a write only packetized memory stream with a maximum packet
- * size of 'max_packet_size'.  The stream is stored in a memory buffer
- * with a big endian 4 byte header giving the packet size in bytes.
- *
- * @param s new IO context
- * @param max_packet_size maximum packet size (must be > 0)
- * @return zero if no error.
- */
-int url_open_dyn_packet_buf(ByteIOContext *s, int max_packet_size)
+int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size)
 {
     if (max_packet_size <= 0)
         return -1;
     return url_open_dyn_buf_internal(s, max_packet_size);
 }
 
-/*
- * Return the written size and a pointer to the buffer. The buffer
- *  must be freed with av_free().
- * @param s IO context
- * @param pointer to a byte buffer
- * @return the length of the byte buffer
- */
 int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer)
 {
     DynBuffer *d = s->opaque;
@@ -785,6 +893,7 @@ int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer)
     *pbuffer = d->buffer;
     size = d->size;
     av_free(d);
+    av_free(s);
     return size;
 }
 #endif /* CONFIG_MUXERS || CONFIG_NETWORK */